Add to your open rate overnight.

If you follow this flowchart and use Mailchimp for a 'weekly newsletter', you can increase your open rate significantly by doing almost nothing.

Send your normal email as normal. Let's say Tuesday at 9AM. If 10% of your audience opens your email, 90% did not. Send the 90% a second email the following day that is the same as the first one. More people will open and you have done almost no work.

That's oversimplifying it tremendously. On the diagram, I added what to do if they DO (Did Open). Get creative.