Thanks to Monica Thomas for this Frugal Baby Tip!
I altered hi-rise briefs that were too big (size 8, which I bought when I was pregnant) to make my daughter's cloth training pants. I cut the underwear at the side seams and the rear side of the crotch panel, discarding the butt portion.
Then I sewed an outer layer of flannel around three layers of terry cloth, about 2 inches wide by 8 inches long, the size of a maxi pad. I sewed this panel into crotch of the underwear, then sewed the open end of the crotch panel (where the butt part had been attached) over and sewed the sides of the underwear to the sides of the center (crotch) panel.
The original elastic of the waistband and leg bands of the underwear function the same in the scaled down version, except that becuse the crotch panel becomes a part of the waist, there are a couple inches in the front where there's no elastic - this doesn't make any difference whatsoever.
And my daughter loves having underwear that look just like her mom's! (I also saved the extra fabric from the butt area to make her coordinating underwear for her Betsy Wetsy doll!)