Have the book copyedited. I hired someone to do the text, the backmatter, the lead-in on the dust jacket front flap, the about the author, about the illustrator, the acknowledgements, the dedication. It cost me about ~$150. The biggest change was to the main text. To use a Tim Gunn/Project Runway statement, I had been in the monkey house too long. I was unable to make simple changes. The main text is only ~350 words. The changes my copyediter made took the whole book to a higher level of professionalism. The changes to the backmatter and other aspects was not as dramatic, but it is nice to know I'm covered.