MOB: Lessons in Lace - Lining up the Scallops

There's a lot to think about as I'm working with this scalloped lace. 

I triple checked to make sure that my sleeve pattern edges/underarm seam were exactly the right length. 

Also I was really careful that the armscye on the sleeve edge matched up just right, so the right length  came out the same on both ends.

 Also the lace slips and moves around a lot, and almost acts like a stretchy fabric. So more pins is always better.