From Chest Binding 101 :
It might seem silly, but you’re probably going to need some help figuring out how to put on your new binder, particularly if you purchased one of the longer styles.
- Put your binder inside out and upside down.
- Step into your binder and pull the bottom of it up, ideally to your belt line. The binder should still be inside out and upside down.
- Use the sleeves as handles to pull the top of the binder (the end closer to your feet) up to your shoulders.
- Put your arms through the sleeve holes and adjust your chest to your needs. You may need to pull the bottom of the binder out from underneath itself if you don’t want it folded under. For others, leaving it folded under may help stop the binder from rolling up.
Don’t be disappointed if you look in the mirror and it looks like you have one big boob in the middle of your chest. You just need to adjust your chest. Reach in from the neck hole and push your chesticles down and out. You’re basically pushing your nipple toward your armpit to achieve the flattest looking chest possible.
I hope it helps!