I just finished a cute pair of bloomers. I started with Simplicity pattern # 2777, but made quite a few adjustments. The waistband and leg bands are elastic with the band on the inside of the leg and in the waistband. I added a cute little black bow and some lace down the front leg seam.
These are a size 22, and suprisingly not too bulky like other ones I have seen. Sometimes they can end up looking like giant diapers.