I buy and use precuts. I like them and I do mix and match. If there is a pattern that is really not my cup of tea, I sort it out and put it in my scrap pile. I will use it someday, just not in the quilt I am making now.
I also have enough yardage that when I need a border then I can match a fabric colour from the pack to a solid/marbled fabric.
I don't recut or check for size-I use Moda, RJR-mostly from MSQC. Love that store!!!