’Tis the season for promotional emails. According to Adobe, in 2017, Cyber Monday alone accounted for $6.59 billion in sales, with roughly 25 percent of sales driven by email promotion. Despite last year’s impressive returns, consumers believe marketing emails from brands have plenty of room for improvement.

An original study conducted by 250ok in partnership with market research firm Lab42 revealed one-third of respondents believe promotional emails are not well-designed. Additionally, more than 80 percent of respondents said they're more likely to take action on marketing emails that are well-designed.

The design elements respondents wish brands would improve may come as a surprise. Readability, ease of navigation, and fit on device screens were cited more often than images, GIFs and videos. Thus, marketers chasing the latest trends in flashy, animated headers and precariously produced video embeds should make sure the basics are well-covered first. In holiday-speak, some marketers are focused on expensive wrapping paper for a gift that might disappoint.

With analysts predicting 2018 will see a 15.3 percent increase in holiday e-commerce sales, retail marketers could be looking at millions of dollars in lost sales simply from failing to implement basic email design best practices.

Below are three ways to ensure your emails convert so Black Friday and Cyber Monday are your best yet.

1. Mind your type and fonts.

Typeface and font selection are two easily addressable aspects of promotional emails. Typeface refers to the design of the letters in the text. Helvetica, Times New Roman and Arial are all examples of typefaces. Font refers to the size and weight of a typeface. Since readability was highly noted as a design issue to fix, email marketers should give both typeface and font ample attention during the design process. For type appearing on a computer screen, many experts agree that sans-serif fonts like Georgia, Verdana and Arial are best. Additionally, increasing font sizes and breaking up large blocks of text could go a long way in improving the readability of your emails. Larger, accessible fonts are beneficial for viewing emails on mobile, which makes up a large percentage of e-commerce shopping during the holidays. Keep in mind that respondents over the age of 55 overwhelmingly cited readability as a key issue, so segment your list by demographic and adjust type accordingly.

2. Use images wisely.

When done correctly, adding images to your marketing emails can bring your message to life. Every image and graphic should represent your brand and business value. Unusual content from your company can scare off readers. Don’t forget the technical side, either. Ask questions such as, "Does the image fit inside the email?" Too large or too small of an image can look sloppy, coming across as unprofessional. Preview your emails on both mobile and desktop before sending. Email can display differently in various email programs — some email clients will even block images automatically. Make sure you’re up to snuff on design best practices, because otherwise, you might get burned.

3. Render like a pro sender.

With survey respondents noting frustrations with how an email fits their device screens, testing should be a priority for marketers heading into the holidays. Performing these tests without a rendering software is impossible unless your brand has an interest in purchasing one of every smart device ever developed. Many rendering solutions produce an exact depiction of what the recipient will see based on the device type so marketers can make important adjustments before hitting send.

Once your emails are in sending shape, it may be tempting to send as many as you can in the days leading up to Black Friday and Cyber Monday. Resist the temptation. Increasing email volume suddenly will be more of a hindrance than a help in reaching your audience. A sudden barrage of emails from your brand will cue spam filters to dump those carefully crafted messages into your recipients’ spam folders or defer your mail to be queued. 250ok’s survey data revealed 70 percent of respondents read marketing emails multiple times a week, so rest assured that as long as your emails appropriately render across devices, are readable and offer a clear next step, your audience will open, click and convert.

Anthony Chiulli is the director of product marketing at 250ok, an email analytics and deliverability platform.