Since I started my detransition back to female I knew it was important for me to have something on my chest to make me feel more comfortable with my body and presentation. I had top surgery 4 years ago so my chest is very flat, and it's highly unlikely my breasts can ever grow back again, so until I can get surgery to get new breasts, I've been trying out different methods of filling out bras.
First I started with socks, then I made stuffings out of socks that I filled with pillow stuffing, then made something more breast-shaped with fabric, hard plastic and pillow stuffing. All of which left me unsatisfied due to difficulty washing them and keeping them dry cause I sweat a lot on my chest, and sometimes it rains a lot in my area. But that trial and error helped me find a size I was the most comfortable with.
So I then ventured towards breast forms, cause a friend of mine had suggested it. I found a website that sells stuff geared towards crossdressers and trans women. It had good size charts for each breast form product which helped a lot, and they were slightly cheaper than what's marketed as actual breast prosthetics but is pretty much the same thing.
I got a size 6 breast forms that were supposed to fit like a DD- or E-cup on my bra size 32 chest, but in reality they fit like a very solid 32D (or 70D in eu sizes) and I can also wear them in a 34C (75C). So they're definitely smaller than I expected, but I'm not really bothered by that. The boob/bra sizing system is mess like no other. I got the cheapest pair of breast forms available, in silicone, which was also on sale, for 107€. Prices for the other ones ranged up to 400€, but most common price was around 180€. The website is "thebreastformstore" and has both American and European domains. I ordered from the uk one to where I live in Sweden and got free shipping.
They were pretty expensive and despite the inaccurate size, I'm very pleased with them and have been wearing them every day since I got them a month or so ago.
Some noteworthy pros and cons about them though:
1.) I can't show a realistic cleavage with them
2.) expensive mastectomy bras are only kinds of bras that seem to work with them (they cost from around 30-40€ each) cause due to the forms' rather wide triangular shape they don't fit in regular bras
3.) I can't wear them while sleeping cause it might break them
4.) they're very easy to clean and comfortable to wear
5.) their weight and feel is very realistic, but look-wise they're not realistic; also the attachable nipples I got with them detach themselves way too easily, and the forms only come in one available skintone
6.) they move with my body somewhat but not as much or as freely as my former, natural boobs did; so as a comparison: quite realistic but the forms are much firmer
7.) they can be glued on with an adhesive but for my every day wear I don't think that would be a good idea for my skin.
But all in all, I'm very happy with mine and glad I got them. I'll likely keep wearing them until I can get surgery. You girls can expect to grow breasts on hrt while I don't have that option in my situation. But I do still ofc have the option of surgery just like anyone.
I've no experience with breastplates, but I can't imagine they'd be comfortable in the long run. I can feel my chest itching and sweating at just the thought of wearing one!
