I find that process to be extremely draining as I am someone who likes to pass off the "detail" tasks to someone who thrives on proofreading and editing. That's why I thrived as a ghostwriter in my earlier years; I would write the book and smile as I handed it off to a crackerjack editor who delved into the painstaking task of proofing and editing. Writers, be kind to editors. They are your friend and they earn every nickel they make!!!
This go around, I've decided to do the entire process myself. I've written my query letter, an email intro of the book and myself and have even developed a spreadsheet of what agents I've queried. I've just begun the literary agent process and it's just as much fun as everyone says it is (that's a sarcastic joke).