Free Subject Line Crash Course

6 rules after writing 1,000+ emails

Here’s how 99% of people write their subject lines:

• They spend 30 seconds thinking about it (once they’re done writing the email)

• They come up with 1 or 2 different ideas

• And then they run with the one that sucks the least

Sound familiar?

Well, I’m here to tell you:

This is a horrific mistake.

Because it doesn’t matter how good your newsletters are or how much effort you’ve put into them. If your subject lines suck, people aren’t even going to open the email in the first place.

And don’t get me wrong - I’ve been guilty of this a million times.

But this is the very first thing you need to work on if you want to get more out of email.

So, here’s a quick crash course on how to (and how NOT to) write irresistible subject lines

6 Rookie Mistakes Killing Your Subject Lines

Let’s talk about the subject line crimes most people are guilty of (and don’t worry if you’re doing some of these, I won’t call the email police).

Mistake #1: Going over 40-45 characters

Usually, I’m completely in favor of long hooks or headlines.

But when it comes to email, you really need to keep it short.

Otherwise, your subject lines will get cut off—and people won’t be able to read them.

And if they can’t even read it, they probably won’t open the email either.

So, as a rule of thumb, aim to keep your subject lines between 40-45 characters max (to optimize for mobile).

Mistake #2: Not using the “preview text” field

Have you ever noticed how sometimes an email might include another line of text right next to (or below) the actual subject line?

Well, that’s your preview text!

Most email marketing tools give you the ability to customize this copy so you can use it as a “sub-headline” to accompany your subject line.

Take advantage of it!

And just in case you’re not familiar, here’s what the preview text looks like (and where it usually shows up):

Mistake #3: Capitalizing the first letter of every word

Subject lines with sentence capitalization (or no capitalization at all) tend to perform better than subject lines where the First Letter Of Every Word Is Capitalized.

There’s no “scientific” explanation for this.

But in my opinion, the issue with using “article capitalization” is that your emails feel like…

Articles.

And most people don’t open their inbox looking to read an article.

They want to read an email (which, if you think about it, is just a digital version of a “letter”).

This is one of the easiest upgrades you can make to boost your open rates, by the way.

Mistake #4: Only coming up with 1-2 variations

It’s almost impossible to write a great subject line out of the gate.

Whenever you’re brainstorming anything (whether it’s a subject line or a song name), the first ideas you come up with usually suck.

So in order to be able to come up with a good idea, you first need to flush all the bad ones out of your head.

And you do that by writing down as many variations as you can… as quickly as possible.

There’s a reason why Upworthy (the news publication site) had an internal rule where their writers HAD to write at least 25 different headline variations before they could finish an article.

Same principle applies here!

Mistake #5: Being clever (instead of clear)

I know, I know.

You’ve probably heard this a thousand times.

Yet, this is one of the most common subject line mistakes I see people make.

They think “clever” subject lines will make people feel curious and click.

When in reality all you’re doing is confusing the reader and scaring them away.

Now, speaking of curiosity…

Mistake #6: Giving away the answer (instead of creating curiosity)

Even though you want your subject line to be clear, you also need to give the reader a “reason” to click.

And you do that by creating a curiosity gap.

Here’s an example:

“You’re not making money because you’re not sending enough cold DMs.”

That subject line is crystal clear.

The problem?

It doesn’t create any curiosity—because it’s giving you the answer.

Instead, you want to make it clear what you’re promising the reader—while also eliciting curiosity.

A better example:

“The REAL reason why you’re not making money.”

See the difference?

Now, I know what you’re thinking:

“Daniel, this is great... but I still hate brainstorming subject lines.”

Fair enough.

That’s why I’m sharing this AI prompt that does the heavy lifting for you:

The AI Subject Line Brainstormer

So here’s one of my favorite prompts to brainstorm attention-grabbing subject lines (without suffering like the Upworthy guys used to).

Oh, and by the way, I’m also throwing you a little bonus after the prompt—so make sure to read all the way through :)