The online holiday shopping season is wrapping up—well, for everyone except the people who order stuff on December 23rd and pay roughly $117 for overnight cross-country air shipping. And the trends are in: People just can’t get enough of Instant Pots, home DNA tests, deep discounts on giant wheels of cheese—and buying stuff on their phones. And while we can’t speak to the first three, we’ll absolutely dig deep into the last one.

On Black Friday this year, 33.5 percent of online sales were made on smartphones, up 29.1 percent from last year.

On Cyber Monday, 36 percent of sales were on phones, up 55.6 percent from last year. Half of visits to eCommerce websites were on smartphones.

Translation: On the biggest shopping days of the year, a record number of people turned to their phones. And next year, we’ll probably do more phone shopping than this year. Mobile eCommerce is here—and it’s trending up.

The rise in mobile eCommerce is especially notable when it comes to your email-driven sales. Smartphones now account for close to half of email-driven orders; that’s 33 percent year-over-year growth. Marketing emails lead to more mobile sales than search and social media combined.

So if a record number of customers are shopping on their phones, and email is the top driver of sales on phones, let’s extrapolate that out: You need to make sure your emails are properly crafted to drive sales on phones.

Now… you probably already have some mobile email strategy in place. Odds are, your marketing emails use a responsive design that looks fantastic on phones and computers. That’s crucial—but here in late 2018, it’s also just table stakes.

There’s more to creating phone-friendly marketing emails than a template that adapts to different screens.

Here are five simple, but highly valuable, tweaks you can implement to improve your marketing emails for smartphones.

There’s been quite a bit written about the art and science of email subject lines, and all of those best practices still apply on mobile. (And rather than encouraging you to read the approximately 175,000 articles on the subject, check out our post on writing highly clickable eCommerce email subject lines for a comprehensive overview.)

When it comes to the length of the subject lines, the consensus is… keep ‘em short.

But when you’re thinking mobile first… keep ‘em even shorter. (PDF)

People use lots of different phones, with lots of different size screens, with lots of different font sizes, with lots of different email clients. So it’s best to keep your subject lines at 35 characters or less.

Here’s an example of a tight, 32-character subject line that comfortably squeezes in an offer and sense of urgency.

Subject lines under 35 characters should safely display in full on every phone. (Or, at least, virtually every phone. If someone’s got 72-point text on a Microsoft Kin, that’s their burden.)

Here’s the same email from above, but with the text size on maxed out (in Apple’s Mail app on an iPhone X running iOS 12.1). You’ll see that at 32 characters, the subject line still fits nicely on the screen.

Fortunately, you don’t need to jam too much info into your subject line thanks to preview text, which we’ll get into in tip number three; 35 characters should be enough for a quick, enticing teaser.

The “from” field in email doesn’t get the same level of attention as the subject line, but it carries quite a bit of value. One of the few studies into the from field found 68 percent of people say the from line is more likely to make them want to open an email than the subject line. (PDF)

The from field is a good place to establish credibility and tone for your email–and your brand. There are a lot of approaches you can take here.

Option 1: You can make it your company’s name, which is simple, but credible, and won’t distract from your offer. And that’s better than just leaving the from field blank to display your email address.

Option 2: You can use it as an opportunity to remind people what you sell. In the example below, a small company with less name recognition–and a name that doesn’t implicitly reveal their core business–uses the from field to reiterate what they sell.

Option 3: You can add your name to give the email a more personal feel (and less of a “mass marketing” vibe).

Whatever route you pick, just like with the subject line, keep it short. You’ve got to stay around 20 characters to make sure you from field will be safe on most phones.

Bonus: Setting up an email avatar

Email avatars show up in the inbox on several email clients, including the mobile version of Gmail, plus Polymail, Airmail, Sparrow, Thunderbird, and more. Here’s an example of the Starbucks logo appearing in Gmail.

Here are the techniques you can use to set up those avatars, which add a nice, professional touch to your emails. Basically, you’ll need to link the email address you use to send your marketing emails to a Google account and a WordPress-based Gravatar.

Preview text (which is also sometimes referred to as pre-header text) is the line that appears either under or next to the subject line in virtually all email clients.

If you don’t specifically set the preview text, the first sentence in your email will show up. That’s a real waste of valuable, limited mobile inbox real estate. Here’s an example of an email where there’s no preview text set, so instead of an additional marketing hook, subscribers see “Want fewer emails?”

The preview text can and should work in tandem with your subject line. If your subject line is a teaser, you can use the preview text to elaborate on the offer.

And vice versa: If your subject line contains your key offer, the preview text can be witty, conversational, a call-to-action, or even a marketing slogan.

But, once again, you’ve got to front load it for mobile phones. Get the most important part of your preview text within the first 35 characters to stay cross-device safe.

People skim emails very quickly; in many cases spending fewer than eight seconds. In about one of seven cases, it’s less than two seconds. So your email content need to catch the eye, promote a product, and, in theory, induce a click in that extremely brief window.

Here are four techniques to help you pull that off.

Focused emphasis at the top. Consider spotlighting one key offer, product, or detail to cater to mobile users. Display it prominently at the top of your email (within approximately the first 250 pixels if possible; here’s a guide to what 250 pixels looks like).

Banner headline. Use one big, short headline to grab a reader’s attention. Chances are, only the biggest text will catch their eye–and will need to inspire them to read on.

Here’s an email that uses a huge date to catch the eye, draw in the reader, and convey a sense of immediacy and urgency.

Prominent buy button. You’ll also want to use a large buy button; one that’s larger than 45 pixels, which is the size of the average finger. Yes, when you decided to start selling homemade jewelry or beef jerky or whatever online, you probably never imagined you’d be sitting here, reading about finger-to-pixel size conversions, but here we are.

Don’t worry about the exact measurements; 45 pixels isn’t particularly huge, so the chances are any prominent buy button will make that cut. Here’s an example of a prominent buy button that’s big enough for any finger.

Make sure to set ALT text for the buy button in the HTML code for your email (it’s not too tricky, even if you don’t normally dig into the code). That’s your insurance policy if someone’s in 3G or on slow wifi–the ALT text will still let them know where to click to buy.

Deep linking. Finally, deep link where it’s appropriate. Since people do less navigating on mobile sites than desktop sites, it’s crucial to take them directly to the product they want to buy. Here’s a good example from Bonobos that doesn’t just link to the product page for their shorts–it also drills down to the specific waist size.

People check email on their phones at different times than on their computers. So with a mobile-oriented email strategy, you’ll want to take advantage of these less traditional times.

First thing in the morning. Is grabbing your phone the first thing you do when you wake up? There’s no shame in that. (Well, there’s some shame, but since about half of us do it, we can all collectively share in the shame.)

If you send your emails in the middle of the night, they’ll be waiting there when your customers make their morning grab for their phones. This timing is especially good if your customer base is younger; two-thirds of millennials do the in-bed phone check move.

Late morning. A study by Google found people are most likely to check email on their smartphones in the late morning. (PDF) So try timing out your sends in the 10 AM or 11 AM hours, which should put them at the top of your customers’ inboxes during their prime email checking time.

At night. There’s nothing quite like finally sitting down on the couch after a long day for some quality time with your family phone. And lots of people are doing it; one study found people are most likely to open emails between 8 PM and midnight. There’s also less competition from work emails at that hour, so there’s a better chance your emails will stand out in your customers’ inboxes.

Of course, when to send marketing emails varies widely by industry and customer base. So in all three cases, testing and experimentation are key to figure out when your specific audience is checking email–and clicking through to buy.

The trend line indicates more people will be viewing emails and shopping on their phones every year, so the time to adapt is right now. And since it’s fair to say half your customers–if not more–will be looking at your emails on their phones, mobile-first is a crucial strategy to at least consider.

Making some small tweaks to the design and copy of your emails can make a big difference to the success of your email marketing campaigns.

• Use a subject line that fits perfectly on the screen paired with some well-crafted preview text. Getting those elements right can mean the difference between someone opening your email while they’re lying in bed–or letting it plummet into inbox purgatory, never to be seen again.
• Don’t forget the from field. Many users rank the from field higher than the subject in terms of what gets them to open an email, so use that to your advantage and make sure they know who the email came from and why they’re getting it.
• Tailor your content elements to the phone viewing experience. That means concisely describing your offer, using a big, banner headline, and featuring a prominent buy button. These pieces all help nudge mobile readers toward clicking to your site and making a purchase.
• Don’t send shoppers on a wild goose chase. People spend even less time clicking around sites on mobile than they do on desktop, so send them directly to appropriate product landing pages.
• Try sending emails at non-traditional times. Reading habits on mobile differ than desktop, so experiment with send times that will get your subscribers’ attention at the times when they’re most likely to be using their phones. (Plus those 4 AM sends will really help you capture the highly-coveted vampire demographic.)

Fortunately, all these mobile-friendly email adjustments are a win-win for you. The tips in this post are quick, easy to implement, and they should help your mobile conversions without any adverse effect on people viewing the emails on their desktop and laptop computers. In fact, things like shorter subjects, better from lines, sharper preview text, and more focused content are likely to help your non-mobile conversions, too.