I use two products from Fourmost. It's a miter sander and miter cutter, they both are fully adjustable from 0 to 90 degrees. I use the miter saw to cut just slightly longer than what I need, double check the angle, and correct the angle with the sander if I am off, and finish off with the miter sander to make a perfect fit and is always square. I paid approx $18.00 ea. but to me it's well worth it. They have a website ( Fourmost.com ). Hope this helps.

Regards,

Pat