What inspires you to click on one email in your inbox instead of another? Odds are, you’ve never put too much thought into it — which means the emails you are clicking on are doing something right.

An email subject line is like a movie trailer: It needs to give just enough information to get people interested in reading the whole email. But this can be easier said than done.

If you’re looking to write killer subject lines for your small business, your search ends here. We’ve narrowed down some of the best tips and tricks used by high-profile companies.

Now let’s get you closer to landing that all-important click.

1. Personalization Is Key

Inboxes fill up quickly. To help your message stand out from the hundreds, or even thousands, of other emails your customers receive, try talking to them directly.

Personalization takes the “mass messaging” angle out of email sends. For example, adding in someone’s name or referencing their previous purchase habits may make it seem like that email was sent only for them.

Of course, sending personalized emails to each of your customers may seem like a lot of work. Luckily, if you have a Customer Relationship Management (CRM) system, you’ll be able to easily personalize your communications with your customers.

For example, a pet-washing service may add some personalization to the standard “Book your next appointment” email to make it stand out.

“Hey Leah, is it time for Max’s trim?”

This is an engaging and click-worthy subject line. A CRM can automatically add your customer’s name, their pet’s name, and the last service they received into your subject line.

All of this makes your email feel special in the eyes of your customer. It acknowledges them and their needs while offering to accomplish them all in one line.

2. Shorter Is (Generally) Better

Most people look at emails on their phones where space is limited. When you’re writing email subject lines, be sure to account for this. You don’t want your perfectly crafted subject line to be cut off because it’s simply too long.

A subject line of 50 characters or less generally has a better open rate than one that is longer. Of course, each audience is different, so it’s important to perform tests to figure out what exactly suits your customers best.

This is probably a good time to mention A/B Testing. A/B Testing is a fancy term for “trial and error.” Basically, you test one type of email subject line against a different type.

You don’t necessarily need anything fancy to perform an A/B Test — just software that allows you to easily see what your email’s Open Rates and Click-Through Rates (CTRs) are.

It works like this: The first time you send an email (your “A” test), write a subject line that is over 50 characters long. Then, the next time you send an email (your “B” test), write a subject line that is under 50 characters.

To truly make it a test, try to make the subject lines similar, removing one or two words here and there, rather than sending something entirely different.

After you’ve completed both tests, compare the results. The email with the best Open Rate wins! Additionally, you’ll learn a little bit more about your audience in the process.

A/B Testing isn’t just for subject lines, either. They can be used on things like buttons, images, websites and more. The more you test, the more you understand your audience, and the better your overall response rate will be.

3. A Quirky Picture Tells a Thousand Words

Yes, we’re talking about Emojis!

Emojis help grab your customers’ attention and instantly convey a certain tone or theme in your email.

For example, a nail salon could announce a 20% off special by adding a 💅. It gives the email some personality, and the customer immediately knows what the email is about.

The important thing here is to not overdo it. Having one or two emojis (at most!) is good, but going three or more is overkill, and you may lose some of the intended message.

Adding random emojis that have nothing to do with your email is also not great practice. It may seem like you don’t understand how emojis work, and customers will lose interest in opening your emails altogether.

The goal is to ensure your customers remember your email, even if they don’t end up clicking on it. Sometimes, seeing an emoji in a subject line is just enough for a customer to remember your special deal without reading any further.

4. Tell Them Why

Finally, give your customers a reason to open your email. Regardless of how you’ve approached writing the subject line, customers need to understand what the email is about, giving them a good reason to click on it.

This means that the content of the email is valuable to the customer. It’s not clickbait— it’s click-worthy. Your subject line earns a click, and the body of the email delivers. Unlike with clickbait, you’re not tricking someone into opening your email.

Creating a click-worthy subject line is about appealing to your customer’s direct needs and ensuring you’re sharing timely information. Spamming customers every day with an email about the same thing will quickly earn your email a trip to your customer’s Junk Folder.

Before writing any email, think about the reason why you’re writing it. If you can easily answer that one question, you’ll be able to craft a better email subject line that earns you the ever-important click you’re hoping for.

Bonus Tip: Avoid Spam Words

There are some words that, due to overuse and abuse, are filtered through email inboxes and can land your emails directly in your customers’ spam folders.

Words like “Cash,” “Free” or “$$$” are considered spam words, and most email servers are sensitive to displaying those kinds of emails to customers.

To avoid getting sent straight to the spam bin, limit use of these words to special occasions.