gigi712

glue baste the seams together, it works every time.

Pennyhal

Sometimes I sew the seam going one way, but when I go to sew the other end, it needs to flip if I messed up my sewing order. So I intentionally twist the seam allowance in the middle of the block instead of at the intersection so that there is not so much bulk at the intersection when I go to quilt it.

If it is a case where the machine feed dogs twist the seam, I undo it just a little ways and fix it.

Ginaky

Years ago I read a hint about taking an old credit card (or those fake ones you get with offers) and cutting a notch on one end, leaving a sharp point. You can slide that sharp point under the fabric at the seam and make sure it flips the way you want it to. The credit card is thin and slide under it quite easily.