I have a super simple easy sew by hand project (with an option for no sew!). Yes, you can do it if you don't normally sew, and you don't have a sewing machine.
I took a scrap piece of jersey fabric. Why jersey? Other than the fact I loathe sewing it in a sewing machine (and don't want to buy it ever ever again), it's perfect for this project. It doesn't require heming since jersey doesn't unravel/fray. You can just use an old shirt you have sitting around.
I laid the doll on the fabric and measured how wide the gap between the legs was and measured how long I needed it so it was the right ride on the front and back. Cut in the general shape of a diaper; however, be conservative with what you cut. You can slowly cut more so it fits correctly. Then I just attached the velcro by hand sewing it on. If you don't want to hand sew, you could simply use the fabric fusion velcro.
Simple project and will help my daughter practice on her dolls while I change baby brother's diapers.
The edges may look a little rough; however, as the jersey pulls a little, the edges will roll and look more finished.