Yes, I always square up my quilts. That will make your borders, especially miter ones to be much more accurate. Take your time. There is NEVER anything to rush over. Think of it that you are doing major surgery on a patient who happens to be your quilt. If you are off more then a 1/4 of an inch off, try to find out the offending block. I would take out any big offender. NOT a lot of fun but you want when you finish your quilt for the happily ever after result. GOOD LUCK !!!