Its a case by case decision with me. Sometimes with a slicker thread (I use alot of Glide), I tend to get knots on the bottom. Even if I am careful and move just a bit, I still get a snarl on the bottom.(and yes I bring my bobbin thread up to start) I try to bury my tiny stitches on the side...if the knot shows up, I bury by hand. With my other threads, it does not seem to be much of an issue. Maybe its just ME! HA! I also try to bury as I go so I don't have tons to do when I am ready to bind...