I've done 5 OBWs and in the body of the quilts I've done a meander in a very fine thread as I didnt want to detract from the kaleidosopes. But I have tried to do something different in contrast thread in the borders.
http://www.quiltingboard.com/t-27510-1.htm
The one I'm quilting at the moment,
http://www.quiltingboard.com/t-34436-1.htm
I am doing a three different thread colour motif in the black borders, hope to finish it today.