I follow the edges. I'm doing it on my large embroidery machine and it has the setting so when I stop, the needle goes down and the foot lifts about 1/4" off the fabric, so pivoting is real simple. Well, not so simple when you are sewing the plate to a full size quilt top! Glad my machine has a very large throat.
Here are more pictures, showing how I plan on combining the plates with doilies. I'll move them around as I get more done, but this is what I'm after. Hope to make a trip to the LQS this afternoon to look for fabric to use for the background.
I went through my tote of doilies and selected some to choose from. The last pic is an idea I'm not sure if I'm going to go with or not. Nothing is sewn down on this plate yet. I made all the circles for a different plate and then didn't like how that turned out. I may decide to save them for a plate that has less movement to start with.