O.K....this is what I've learned about using Thangles.
First, is that chain linking Thangles is very easy and should be done. I knew this already, but just thought I'd state it again!!
This is a NEW discovery.......don't sew exactly on the dotted line!! You want to sew a hairs length into the seem allowance so that once you've ironed them out they will be the size you want or slightly bigger so they can be squared up. I found it was hard to do this, however, so what I ended up doing was using my quarter inch foot. I used the SOLID LINE as my guide. By keeping the edge of my 1/4" foot on the solid line I was achieving the effect I needed. So if you find your Thangles not coming out quite as you'd like....this may be the trick you need!!!