A friend of mine in nursing school is having a baby! And given he frequency with which he wears space-themed shirts, I thought this would be the perfect plan. I looked up a constellation map online, and found a portion that would be somewhat square. I also wanted it to include my favorite constellation (Cassiopeia) and a famous one (the little dipper). I happened to use August 2012.
Here's the final result:
And a closer look at eat of the constellations:
As you might be able to tell, I made circles for each star, and then made chains the approximate distance to the next star. I built out from there. At the end I went around the circumfrence twice to even it out a little.