Here's a quick pattern tip for making kids pajama pants. I didn't want to buy a pattern just to get some 1 seam PJ pants for Kate, and I was feeling kind of lazy about making 2 seam pants. You can abut the pattern pieces from regular 2 seam pants to get a 1 seam PJ pants pattern.
Lay out 1 pattern piece, and then put the other one next to it. I use the "alter pattern here" lines to help me line it up. It doesn't have to be perfect, these are PJs after all! Then cut around the entire shape to get your pants pattern. Viola!