I found a tute on Youtube from The Crafty Gemini that was pretty good though if any if you are still having trouble.
I tried that in the past and hated it. My current preferred style that sort of works is to trace the pieces on fabric, cut with double seam allowance, stick a needle through the pattern in each end of the line to be sewn, and stick them through the tracing on the fabric as well. I let the needles stick straight up and pin along the side. Works for me. Better anyway.
(actually I didn't trace, I printed an extra pattern, cut it, and just pinned the pieces on and used them as "trace" but it was hard getting them to lie flat against the fabric to stick the corner needles in the right place)