All have given you wonderful suggestions.
The time spent in preparing the quilt for quilting makes a huge difference in the quilting too. I have tried spray basting, only to have a gummed up needles and machine which then produces skipped stitches. I no longer spray baste because of that and also because the stuff is bad for one's lungs.
Instead, I hand baste using the Sharon Schamber method:
http://www.youtube.com/watch?v=bhwNylePFAA. I found this method to work the best for me. It does take some extra time to do this method of hand basting, but well worth the time.