Breast forms, OMG long long ago in a far off universe I used to use bird seeds in cut up stockings. All my friends used to joke I was going to get attacked by a flock. Actually kind of miss them, nice perky shape but they got weevils. Any who a friend gave me hers when her own breasts started to fill in. Old school silicone ones, think they were triangle shaped. I have tried a few different types and shapes but I found silicone ones that fit into a full coverage bra worked best, and tear drops, plus I liked the ones that could be glued in place as I tend to not wear a bra if I can help it. I did blow a thousand bucks back in the day for a perfect skin tone glue on to match with little hand painted freckles and vanishing edges silicone forms. These were very realistic but also had a bigger back profile and they tended to get sweaty if I was doing much. As this is a PG site I won’t post a photo but people could not tell unless about a foot away from them and I was topless. I have never tried a breast plate or shirt or full body suit type but my guess is hot and sticky for everyday use unless just bedroom play or photo shoots and even then but vanishing edges and perfect skin tone would be a must for me if I had to do this option. If not the edges are going to show unless you cover with something, and if you go that far mine as well cover you bra straps and stuff, even for swimming you can get a full coverage suit to hold all in place. However there are other areas to consider when wearing a skimpy swimsuit or skin hugging stuff.