They’re so little – just 50 characters – but email subject lines have a lot of power to influence your open rate. Done well, a subject line can be just the hook that someone needs in order to open an email. Done poorly, and you’re likely to get dumped into the trash box with nary a second look.

One of the worst things you can do is attempt to craft an email subject line without having a goal in mind first. That goal may simply be for someone to click on something – or it may be for them to buy a product. But having the goal is imperative.

Want to learn more about subject lines? This graphic can help.

How to Write the Most Important 50 Characters of Your Email