When I first started sending email campaigns, I thought the content inside was what mattered most. I’d spend hours polishing paragraphs, designing visuals, and adding links only to watch my open rates sit around 10–12%.

It took me a long time (and a lot of testing) to realize something simple but powerful: no one reads what they don’t open.

Once I started focusing on subject lines, timing, personalization, and curiosity triggers, my open rates jumped by more than 40% consistently.

Here’s exactly what I did.

Step 1: Writing Subject Lines That Sound Human

The biggest breakthrough came when I stopped writing “marketing emails” and started writing real messages.

Here’s the difference:

 “Unlock 30% More Engagement With These Tips!”

“I tested something last week here’s what worked.”

The second one feels like it’s from a person, not a brand.

I tested dozens of variations across different lists, and the best-performing subject lines had three things in common:

• They sounded natural, like something you’d text a colleague.
• They used curiosity, not clickbait.
• They were short under 50 characters.

Here are a few of my personal winners:

• “This might be awkward…” 39% open rate
• “Can I be honest?” 37% open rate
• “Quick question about your website” 41% open rate

I keep an entire folder of my best subject lines now. If you want to see how I organize and test them, I break it down step by step in  Email Marketing.

Step 2: The Secret Power of Preview Text

For years, I ignored preview text  that little snippet next to your subject line in the inbox. Big mistake.

After I started writing preview text intentionally, my open rates jumped another 6–8%.

Here’s how I use it now:

• Treat it like the second subject line.
• Finish the thought started in the main subject.
• Keep it under 100 characters so it doesn’t get cut off.

Example:

Subject: “This might be awkward…”

Preview: “But your last email probably didn’t reach as many people as you think.”

It creates curiosity without clickbait and that’s the key.

Step 3: Timing Matters More Than You Think

Every article online will tell you to send on Tuesday mornings. I did that too, until I tested other times myself.

Here’s what I discovered after sending over 100 campaigns:

• Tuesday 10 AM is good, but it’s also everyone’s favorite , meaning competition is high.
• Wednesday late morning (10:30–11:30) worked slightly better for my B2B audience.
• Friday afternoons surprisingly performed best for my eCommerce campaigns.
• Sundays got higher open rates for personal, newsletter, style emails.

The big takeaway? Don’t follow generic “best times.” Test your own list.

I share how I track open and click patterns across different time slots in (“Analyzing Email Campaign ROI”). It’s one of those small optimizations that can move the needle quickly.

Step 4: Personalization Beyond First Names

Personalization used to mean adding someone’s first name at the top of an email. Now it means relevance.

When I mention something someone downloaded or clicked on before, engagement skyrockets.

“I noticed you grabbed my email list-building guide last week. Want to see how I used it to grow my list by 3x?”

That’s 10x more engaging than “Hey {FirstName}, hope you’re doing well!”

To scale this, I use behavior, based tagging in ConvertKit and Klaviyo. It lets me trigger emails based on actions, not just names.

I detail this entire process in (“Building an Engaged Email List”) that’s where I show exactly how segmentation keeps subscribers active long-term.

Step 5: A/B Testing Everything

I’m obsessed with testing now  and it’s how I learned what really works.

Every campaign I send includes one small A/B test, like:

• Two subject lines
• Two send times
• Two “From” names

I use ConvertKit’s native split-testing feature and sometimes even test manually by splitting my list.

One test that stood out:

Version A: “How to Write Better Emails”  22% open rate

Version B: “I rewrote this one email and it tripled conversions” 39% open rate

That’s a 17% jump from a single tweak.

If you’re just starting, pick one variable per test and run it at least twice before deciding what works. Small wins add up fast.