This is what I did
1) I started with a pair of pants. You can actually use non maternity pants, they just need to fit in the hips and legs.
2) I then cut off the top of the pants. I cut the pants to where it is right under my belly
3) Then I took a stretchy shirt (mine got bleached, so it was perfect for this).
4) I cut off the bottom 6 inches, I folded it in half to make a 3 inch band
5) I then pinned the band onto the pants
6) I then sewed it onto the pants. I used a straight stitch but kinda wish I used a zig zag, just for strength
And here they are. Much better than before, I love the under belly band! As you can see, I also turned them into shorts, it's just too hot!