I was watching a video last night in how to draw Celtic designs by drawing a grid of dots, after some halfassed attempts on regular lined paper I moved to graph paper. The video said to use a grid of 4x6, but I found this a bit too much, so 4x4 worked, and it wasn't until I drew a line going around it o. The inside to make sure I had the under/over pattern right, I noticed there were three interlocking rings. And of course I had to give it an Irish colour scheme :p