I find it is important to keep the same weight of thread in the top and the bobbin. My favorite is Star thread which is a Coats and Clark off-shoot. I have used it for sewing, topstitching and quilting. Sometimes, I just use up what I have.
Some people say to use only 100% cotton thread with 100 cotton fabric. I think that is a little overkill. My goodness, how much strain will be put on a quilt that the oly-wrapped thread will tear the fabric?