Thank you for the replies. I have not been floating my top. I have been pinning it to the leader for the top. It's just how I was taught. But I think I will try a few things that were suggested here and see what I like. The 2 I like best are to just do as I have been, with basting the bottom b-4 quilting the last bit, and floating the top with basting the sides as I go. I've tried it with and w/o basting the sides down as I go, and don't really have a strong preference one way or the other as I don't see that either one makes a big difference. But I have known others who really like one way or the other.
Good thing I have a bunch of things to quilt, it'll give me plenty of practice.
I will say, I don't love pinning, so perhaps floating the top will be something I like, as I will get to avoid 1/3 of the pinning.