Address the editor's final queries, hand in the finished manuscript, and then bask in the glow as 11 months of writing plus 9 months of rewrites draw to a close. That's the best part of being an author: completing something.
I don't sit still for long, and after handing in the manuscript I jotted a few thoughts down for the back cover blurb, emailed the production manager about covers and packed up books for winners in my various competitions.
My publisher has first and final say in all design matters - covers, blurbs, etc - but they do encourage input, and I don't take much encouraging. I was reading Jennifer Fallon's blog post about palm trees which explains the publisher/author relationship better than I can.
Simon Haynes is the author of the Hal Spacejock and Hal Junior series (Amazon / Smashwords / other formats)