It's important for me to note that I attempted a Poison cosplay a while ago, and it was just awful. At the time, I knew nothing about makeup, I wasn't in any sort of good shape, the wig didn't even look right.
Now that I've improved my skills quite a bit, I made it a point to revisit this costume. The first thing I decided to do was completely rework the costume. In the Japanese storyline Poison is a pre-op transgender individual (or a "new half"), a fact that I greatly admire Capcom for including. However, her body doesn't look much like a man's in the slightest. Most men would have to cinch their waists to get the curves she has. Keeping that in mind, I decided to elongate the sports bra into a tattered tank. It stops just above the belly button, but lays low enough for me to properly cinch myself up. I may have to use a few strips of fashion tape to keep it from riding up.
This costume was remarkably easy, as the only parts of its construction that required a super amount of effort were the tattering of the top/shorts, the modified handcuffs, the buttons on the shorts (which can't be seen very clearly in the image, but have tiny silver skulls on them), the Swarovski crystals, and the wig (which will be included in a later pic). I actually had to join two wigs together to get the volume and fullness I was searching for.