The thread I use is the finest quality 2 ply that I can find. I like the Mettler, fine embroidery, size 60/2. That number means size 60, 2 ply. This is a silk finish thread that pulls through the quilt like a dream. I have tried the cheap, hairy basting threads on the market and they take forever to pull through the layers. I want to baste fast and easily.
My basting rows are approximately 6-7" apart, about the length from my thumb to little finger, so that is my measuring stick. If the pattern is 6" blocks, then it is along the edge of every block, so sometimes I am able to just use the quilt pattern to gauge the distance. I never baste over the top of a seam where 2 blocks join, always to one side of it when I do a row of basting.
You always baste from the center out so find the center of the quilt and do one row to the top, one to the bottom, and one to each side. These are your center lines which all other basting will start from. When I am finished I have rows going both directions all over the quilt, in other words it looks like squares, or a plaid. Your basting rows are your guide when quilting to see whether the top is moving. If, as you approach a basting row, the top starts humping up, you know you have to ease it in before you reach the basting row.This little quilt is another old one, made from Debby Caffrey's "Noodle Soup" book. All of the blocks are on the bias so it is tricky keeping it square to sew on the border.