So i'm a transboy and i really need to bind, but i don't own a binder. I'm currently using a tight vest rolled up and a sports bra, but it's kinda useless. I don't want to get a binder yet as a) my parents would notice and b) i wouldn't wear it to school because i go to a single-sex school and being flat chested amongst loads of cis girls would be awkward plus i'm not properly out to anyone there yet.
Well I wear two sports bras - one the right way and one backwards. Because I'm a 32DD it flattens me enough that I like how I look but not enough that I'm noticeably flat chested. Maybe you could try that? Of course it depends on how big you are; if you're smaller then maybe just one sports bra so it's a compromise? You're flatter than before (yay for you!) but not noticeably flat (yay for not standing out).
Yeah, before I got my binder I did the same thing Lacybi did with the sports bras. Just be safe with it and follow the same rules you would binding- no more than ~8 hours, and don't put on more than two. (I learned the second part the hard way lol)
There are a few homemade ways. Buy and wear one sports bra a size lower than what your size is. Get and old pair of thick/strong Leggins or an old shirt and cut out a length that goes around your chest, when you have the right size sew the ends at the back together. (this is what I do with one of my old flexible knee supporters, strong, bit of breathing space, easy on and off) Three pairs of tights, cut off the legs your left with the top bit which will be tighter than the legs. However this isn't as effective if you are a larger cup size :c NEVER EVER EVER EVER EVER EVER WEAR ACE BANDAGES OR DUCT TAPE These are not meant for binding, they don't move with your body. They restrict breathing, can build up fluid in the lungs, can even break ribs, some transmen have been left with permanent scarring from using them. They are very dangerous. Remember whilst you are binding if you feel pain take it off immediately and have a few hours rest. If the pain continues don't wear your binder again until you've seen a doctor. Also don't worry about being flat chested in a school full of cis girls, as long as they're accepting t your identity it shouldn't be that awKward, I go to an all girls school and there are three people that bind at school and I'm gonna start soon too. Anyways good luck, I hope you find something that works for you
Sports bras might be your best bet. Before I got a binder, I used those stomach shapers (would make your stomach look flatter, and lift your chest) and it was a bad time overall for me. I had horrible dizzy spells and I had to stop binding for a while because it messed me up so bad.