Not watching for wrinkles on my face, though there are many more every day. As the machine quilting on the Log Cabin started, the first row of stitches produced two wrinkles on the back flannel. I had forgotten to put the walking foot on the machine!
The walking foot is the attachment that works best for quilting. The machine has what is called feed dogs that grip the fabric from the bottom and pull it along for the stitches. The regular machine sewing foot just presses the fabric down to work with the machine feed dogs on the bottom.
When there are the three layers of the quilt (top-batting-back), there is a pretty good chance that the back will wrinkle or pucker with the regular attachment. That is what happened on my first row. I had to pick and re-sew in 2 places.
The walking foot also has feed dogs on it. The little arm near the top fits on the needle bar, so that the two sets of feed dogs work together to make the stitches as the needle goes up & down through the fabrics.
I do not think I will trust the walking foot to just zip perfectly through the stitches, and plan to check each row out every time. I lucked out with the quilt I just finished and think it had a lot to do with the fabric choice on the back as well as how well it got basted.