The best email subject lines are the ones that get your emails opened. The subject line is not the first thing your recipient looks at. That’s the From name. But after that, the subject line is going to get your subscriber to open your email—or not.

Research finds 47% of recipients open an email based on the subject line. That’s almost half of the names on your list who will make a decision to open your email or ignore it based solely on the subject line.

And if your email doesn’t get opened, what’s the point of sending it? Without an open, your email message goes unread. If it’s not read, it’s not acted upon. Any email not opened is an email wasted.

So, take the time to figure out the best email subject lines for your business, those that help your emails stand out among the inbox clutter and get your emails opened—and acted upon.

Relevance is key, of course, but there are other ways to up your open rates. Below are the top five mistakes I see marketers make plus ways to avoid them, so you can create the best email subject lines for the best open rates:

Mistake #1 – Not creating a sense of urgency

It’s important to convey a sense of urgency to prompt your subscriber to open your email. Using key words like “this week only” or “for a limited time” are a tried-and-true approach. You could also test wording like “last chance,” “early bird special,” or “extended offer” to see how they perform for you.

Mistake #2 – Not saying “Thank You”

Studies have shown that using Thank You in your subline dramatically increases the open rate. Everyone likes to be thanked and those two words can help increase your open rate as a result. Try weaving “thank you” into your subject lines with an A/B test, one with and one without, and compare the results.

Mistake #3 – Your subject line is too long

With our declining attention spans, a subject line that is more than 10 words just won’t drive the results. Getting to the point with a shorter subject line can help your open rates. (And see mistake #5 about the short subject line length on mobile devices…)

Mistake #4 – Not personalizing

No one wants to feel they are part of a crowd, just one of many receiving a generic email blast. People want to feel special. When writing the best email subject lines, you’ll treat your subscribers like you are talking directly to them. Research says emails with personalized subject lines are 22% more likely to get opened. Simply using their first name and a “loyalty” status can increase the likelihood that they’ll open your email.

Mistake #5 – Not optimizing for a mobile open

According to EmailMonday, 49.1% of emails are read on mobile devices globally, so optimizing is critical. Many mobile email apps only render 35 characters of the subject line, so make sure your personalization, “thank you” or sense of urgency is upfront. Subject lines any longer than 40 characters won’t be visible until the email is actually opened.

Investing your time in writing the best email subject lines will yield the results to pay you back for that time. And utilizing your ESP’s ability to do A/B or multi-variant testing will show if you are on the right track as you figure out what the best email subject lines are for you and your email marketing goals.