I start quilting off the top in the batting and them move onto the top. I do the same thing to stop quilting. I quilt right off the top into the batting. IF I have to stop in the middle of the quilt to change a bobbin. Then I take A stitch and then do as the others have said to pull the bobbin thread to the top. Once I am done with the quilting I will then tie a knot in the threads and thread them through a needle and then hide them inside the quilt. kinda between the top/in the batting. They don't come out and you can not tell where you stopped and started!