Gearing up to query my next book

So last year around this time I finished Last Wish (maybe it's better to say I got sick of it) and started submitting it to agents. After multiple failures I had high hopes it would be the book that would get me an agent and went into the querying process with excitement. My early queries didn't gain any traction whatsoever (though I did get a few personal rejections) but when I participated in a Writer's Digest Boot Camp the agent I worked with requested the full manuscript...and then sat on it. When I emailed to see if if she'd had a chance to read it she said she'd been too busy and hadn't gotten to it yet. A follow-up email months later didn't even get me an answer. After some further edits I got another full request last fall, but that ended in a rejection as well, which was a a real kick in the ass. So. With a new manuscript in hand I'm taking a different approach this time. I've hired a free-lance editor I know to do a developmental edit on the book and have also signed up for a  Writer's Digest boot camp and a First 1200 Words workshop. I'm going to put this thing past a couple of agent's eyes before I ever even think of cold-submitting it to an agent. I'm hoping this expense at the beginning of the process will pay-off and get this book over the hump. And if it doesn't happen? Well, there's always the next book...