I never get squared either. Here's a tip my mom told me. Pick out the smallest one, square it, and make all the others the same size - here again - who's to know but you. I have been quilting for over ten years. I have no idea what a totally correct block is supposed to look like when it is finished. Mine never are. But they seem to turn out. Last year I was asked to make a quilt for the Susan G. Komen Breast Cancer Three Day Walk. Sure, I said - yah!!!!! It turned out beautifully, it made over $1,500 in a raffle drawing and I was asked to make another one this year and am in the process of making another one, this being a Sampler Quilt with 35 12" blocks and at the same time a Sampler Quilt for our granddaughter that has 15 12" blocks. Don't beat yourself up. I seem to do my best work when I am listening to an audio book, having a glass of wine or pop and be able to get up and walk away if you are a little perturbed at what is going on. You'll get a new perspective when you stick your nose out the door and breathe or talk to someone on the phone.
LISTEN TO ME - I AM 71 YEARS OLD AND PROBABLY A HECKUVA LOT OLDER THAN YOU AND IF YOU DON'T LISTEN, I'LL SIC MY MOTHER ON YOU - SHE'S 93 AND STILL QUILTS!
Enjoy the day and enjoy what you are doing! Edie