hello. I have cotton forms I call sleep firms. they aren’t very large n there is no bounce, so I wear them to work out or sleep in.
I use silicone forms, 2 sizes, D n DDD. I was wearing a form holding bra under a good Playtex full coverage bra, n often add a snug camisole which helps hold them in place. go with good bra but you can find Playtex or other name brands for less than 60 per. I think I usually buy a group when I see 20ish per. mine can glue on but I haven’t tried with size I worry they’ll fall off n I’m often changing to butch to see mom, so gluing becomes impractical..I usually wear I high necked shell under my blouse or button my blouse up pretty high to keep everything hidden.
now working with vendor on getting swim forms from aomona to match in size n mastectomy suit too.
hope this helped