Maybe your bobbin tension is too tight. Are you using the same weight thread? You can purchase a special bobbin case for some machines for quilting/stippling.
I usually start in the center of the quilt and quilt outward.
When layering the quilt, I use masking tape to tape the corners of the backing to my kitchen floor; then place the batting on top, then the quilt top and pin. Next I flip it over to check for ripples and try to get it as smooth as possible. (My knees and back do not like this technique! LOL)
Hope this helps.