Here is a picture of the cloth pull ups I made:
The outside fabric is cotton and just scraps that I had in my sewing box. The inside is flannel scraps. I put elastic in the back and the by the legs and in the tabs. The elastic was the worst part. I would have loved to not use elastic, but that is what helps to hold in the pee :)
I have found that they are not 100% leak proof. But he tends to pee. A. Lot. So on the nights when he doesn't pee as much then his jammies are still dry but on the nights that he doesn't . . . his jammies get wet - but usually not enough to wet his bed.
Here is one of the tutorials I used.
Here is a video tutorial. It is a 4 part series - once you click on the first video you should be able to find the rest.