My little guy grew out of pajama pants that fit. So rather than buy new sweats for winter, I took it as an opportunity to use some of my fabric stash I need to use.
I used another pair of his pants that fit him a little big as my pattern, you can see the new pants are a little long for him.
I made a printable instruction sheet here for using your own pants as a pattern to make pajama pants, and there are many more in the sewing blog world.
For this set, I used some red sweatshirt fleece left over from my fall jacket, and some thick grey fleece. I don't bother to hem fleece on these pants. It doesn't fray, and these are just pajamas.
Lately he has to carry his entire Toy Story collection everywhere. Big Buzz, Big Woody, Baby Buzz, and Baby Woody.
The next two pairs were flannel remnants I had. Flannel isn't as warm as the fleece, but still comfy. I did hem these ones, although they are still too long.
I put his flannel pirate pants on and RJ said: "Pirate!" and ran away. I was getting up to go find him to snap a photo of his pants, when he came back with the Halloween Pirate Skull we made. So he dropped Toy Story long enough to pose with the pirate skull wearing his pirate pants.
I know lots of people give pajamas on Christmas Eve as a tradition. They are easy if you make them, and while you're cutting one out, it was nice to whip out a whole batch at the same time. You can also embellish with applique, paint stenciling, etc. to further personalize. I thought about putting words across the butt of his pants, as a joke. Like adults who wear words like "juicy" on the bum of their sweatpants. In the end I got lazy and just left them all plain, but maybe I'll go back and add "squishy" or something on his bum.