I use cotton or a cotton/poly blend to piece with--both top and bobbin. I bind with Coats all-purpose when I sew down the back--it doesn't tangle or break as easily as others, especially cotton. In the long arm I use almost exclusively SoFine #50--it's thin enough, comes in lots of colors, and works well in my Gammill. But I will when it works with the quilt use Permacore, Glide, Marathon's trilobal, and a couple that I use up on charity cause I don't like the way it runs in my machine--too linty, more breaks,too thick to do much intense quilting, etc--King Tut, YLI cotton. Get a cone of each brand you are interested in and try them out.