A tried and true strategy for Indie Authors is the box-set or collections. Gather all the titles in your series or a collection of your stand-alones and release them with a special price and you will find traffic to all your titles increases. And of course, the prettier your box set cover the more successful this strategy will be.
With your box-set package you will get an original cover for your box set (either entirely original or based on your existing covers) along with a 3D layout for Kindle,Kobo, Smashwords and Nook and a 2D layout for iBook. Your cover can also be laid out for a paperback omnibus print edition.
Here are some examples of box-sets I’ve done: