I always cut it all out. But I just finished a quilt that called for two pieces to be diagonally sewn together. So, impatient me just dug right in and cut and sewed the diagonally just like I prepare my binding. Turns out the diagonal sewn pieces had to be sewn the opposite of how I normally do binding (piece on bottom right side up, piece on top wrong side up with the bottom piece sticking out to my left.
Well, from now on I will do one block and sew a practice block. I needed to have the piece on the bottom sticking out to my right which totally changed the way the diagonally sewn line looked in the finished block. I have probably confused everyone and I'm sorry, but at least this is off my chest and I can stop beating myself up.