I also had and sometimes still have your problem. When I use spray glue (just brought back some elmer's washable school glue to try) plus safety pins, it seems to work the best for me. I was able to do a king without problems when I used lots of glue.
But I don't starch the front and back, either. I can see that would help, but I don't really have starch easily available and don't want to get into making my own. I also use poly batting. It is definitely true that the thinner the batting the easier it is to NOT get puckers.