I had a difficult time finding something to wear to church on Sunday, so I came home and got started on my maternity sewing. The skirt is made out of a sheet I bought at a thrift store ages ago as practice material for Rachel's dress. I made up the pattern, but here is a tutorial from Sew Mommy Sew: Maternity Skirt Tutorial. This took about an hour. This was my practice skirt, I have some really nice material I'm going to try next. The top is some knit fabric I bought from JoAnn.
The shorts are a pair of slightly-too-big pants I already had, with holes in the knees. I used more of the knit fabric. I marked where I could zip them up too, then cut them at that mark, and removed the zipper. I sewed the fly shut. Then I made a band of knit fabric 5 inches wide, and the length stretched as tight as I could around my tummy. The band is folded in half lengthwise, and stretched to fit the waist of the jeans then sewed on. Took about half an hour. These were "practice" too. I'm going to make a pair of pants next, and I'm going to use a much wider band, maybe 10 inches, folded in half. These don't come up high enough.
Here are some helpful sites for maternity jeans:
Craftster: DIY Maternity Jeans with tutorial
SewChic: Tutorial: How to Convert Jeans into Maternity
ETA: I ended up picking open the seam of the knit fabric on the shorts and inserting 2" elastic after wearing them a few times. Easier and faster than redoing it with more knit fabric, and hopefully they will stay up better.