We do Christmas pjs at our house, but we don't do "Christmas" pjs as in they have to be Christmas-y. The kids just get new ones on Christmas Eve.
This year Sophia wanted pants and a shirt. Here's what I came up with:
The flannel came from JoAnn's. The pattern I used was Simplicity 3669 and made them drawstring pants. I was able to get both pieces out of 2 yards of fabric. Not sure if I'll be able to do that much longer.
I added the yellow for a little contrast and pop of color.
Clara just wanted a simple nightgown. She likes cats, so I picked up this flannel at JoAnn's for her pajamas. For hers I used Simplicity 5695 and modified it a little to make it more comfy.