Hang it up, back off about 15 foot and see that most things you think are mistakes are not noticeable to anyone else.
I once went to an exhibit where a well known national teacher had her quilts. Absolutely beautiful quilts. When I got really close to a couple of them I found that all her points DID NOT meet perfectly. The overall effect was breathtaking, but close up, there were some flaws. Also if you have a light dark piece that misses meeting by just a smidge, use a permanent marker to match the darker fabric and add a bit of color right where the pieces meet. Works to cover small piecing errors.