Those of you who have been around a while know that a couple of years ago, I was hit with 105 rejections. You also know that after that things changes and I have a high request rate for the limited number of queries I send now. This is in part because I learned to write a blurb and in part because I became better at plotting. But I use the same technique for both plotting and blurb writing.
If you're interested in learning how to let your plot write your blurb, I'm teaching a class on just that in April for OIRWA. It's a two week course available online, and you'll finish the class with a completed query. AND you can do this even if you haven't written the book yet. You'll still finish the class with a completed query, and it should be pretty close to what you will use when you query.