Glue is pretty commonly used by quilters, who have very exacting standards about where pieces need to be. There's no need for special fabric glue, regular washable glue works just fine, since the glue isn't structural, it's just for assembly. On the rare occasions that I need to do this, I use a glue stick. The last one I had was neat: it went on purple, and then dried clear, which makes it easier to see where you put the glue.
I wouldn't use glue on anything that isn't washable (or at least spot treatable.), though.