I quilted 1/2" inside all of mine, and pulled the thread a little tight because I like the puckery look of a quilt. It has also been washed and dried by machine. Here is a pic of it closeup. I just finished it after Christmas. Maybe this will help. There is a pic of the full quilt in the pictures section.
Also there are other designs you can make such as diamonds when piecing the hexagons. There are alot of good pics on the web.