I agree with IQ2. What works great for me is sew just a few inches at a time, spreading the material out in front of and behind the needle using my thumbs and index fingers, with hands flat as possible and all fingers spread out. If I see that I may be approaching a pucker (like possibly 8 or 10 inches away), I can kind of manipulate the top fabric over the bottom and ease everything to eliminate the problem. Yeah, practice. =)