I think for many of us our piecing inaccuracy lies in our cutting. I frequently forget to use the same position on my ruler when cutting strips/pieces. Am I this side of the line; that side of the line; etc. When I'm not cutting/sewing I keep thinking I should put a piece of tape (even just a small one as a reminder) of where I want to read my cutting measurement. Then, of course, when I get into the sewing room, I forget all about doing this. In the end, I feel my work is 'good enough'. My pieces/points match where they are supposed to. Sometimes my seams might be a tad small but who is looking at the back of my quilt? As long as it's going to stay together (which they all have so far), does it really make a difference?