How to get more email opens with 11 great Subject Line suggestions

Segment and Personalize: Each list segment should have appropriate and different subject lines. Segments that contain the same version of your email should also have a subject line tailored to the recipient’s interest.
You do not want to use someone’s first and/or last name in the subject line and consider it personalized email.  In other words, avoid using a subject line like “Rountree, This Is Your May Newsletter” followed by generic content.
Brand Your Subject Line: (another great Subject Line suggestion.) Use a consistent FROM address. Consider including the name of your company, usually in the beginning with enclosed brackets, so it become familiar to the recipient.
Use a Consistent Style: Subject lines need to change with every mailing, however, once you find the style that works best, continue to use it. Ask someone else to write, edit or review it.  You can also use a tool like check my subject line https://www.subjectline.com/ to see how its ranking and see if you’re hitting all the right areas.
Send Subject Lines to yourself: Compare it to the other messages in your inbox.  Is your email subject line  compelling, interesting, or boring? If you are the recipient would you open it or delete it?
Monitor your inbox for ideas: Figure out which email subject lines intrigued you to open it immediately.  Which ones move you to delete it?
Check your open stats. Analyze the type of subject lines that produce the best open and click-through rates.  Open rates indicate the most obvious measure of the success of a subject line.  Are there more opens with information, a coupon, or a sale?
Consider Context: Use the information you know.  What events are coming up, what is happening in the world, what are people talking about?
Realize what might get filtered:  Use a subject line analyzer: as tripping a spam filter is undesirable.  Send test messages to your free accounts: Yahoo, AOL, Hotmail and Gmail to make sure your email message doesn’t trigger a filter.
Test the length: Data suggests email with subject lines less than 50 characters have higher open rates.
Write Early: Some marketers seem to wait until the last minute to write subject lines.  As you pull together your email content, draft up potential subject lines.
Push the envelope:  Take charge, be aggressive, creative, or specific.  Try different styles, and test for the best results.  You may find one segment of people (men for example) like the gentle subject line approach while another segment may readily open aggressive subject line email.

Test, Test, and Test Again

Subject lines are the easiest component of email marketing to test.  Split your list in half, fourths or eights, and test a different subject line in each split.  

Remember subject lines are one of the most important components of a successful promotional or newsletter email.  They should reflect your goals and help direct recipients to take the desired action you want them to take. It’s not rocket science but close to it.