I am going to side with the "try not to be a perfectionist" group here. If you keep that up, you take the fun out of what your doing, and when you do that, you just keep more mistakes, and then pretty soon, you have put what ever your working on over in the UFO pile. Making quilts is supposed to be relaxing, fun, enjoyment, etc... try the suggestions above and they are sure to work, but don't fret if one is not perfect : )