don't know if you are using a long-arm or a sit-down....but all the suggestions are good.....also needles flex some and sometimes when doing curves you may be having some of this needle flex as the quilt is moved...solutions to that could be a larger needle or slowing down …...I did have a big problem with the occasional huge bird's nest with my new Bernina….finally took lots of pictures when it happened and then left the bird's nest in place and took the machine to the shop.....the tech was there and looked at the pictures and said it was very helpful as was leaving the bird's nest in place....it only was happening occasionally....turns out the timing was ever so slightly off so when the stars aligned and the wind blow from the right direction....a bird's nest happened...good luck!