Just going to cut to the chase here and be honest.
You don't need a red rag hanging out of your back-pocket or a tattoo that says 'Blood' to let people know what you're representing and where your from. It's quite stereotypical and I want this faction to be somewhat unique at least.
Here's what I thought of. If you want to RP having some tattoos only thing I could possibly suggest is either a simple 'B' that would stand for Blood & Belmont at the same time. Or just Belmont.
I don't want anyone wearing rags, that's just stereotypical.
Clothing. This is the most amazing way to represent what you are and where you from. I'd suggest colors such as Green, representing the money that we make. Red of course for us being a small clique affiliated to the bloods. And last but not least Black & White.
Clothes that I would suggest wearing for gang affiliation: Chicago Bulls slippers, jerseys, snapbacks. New York Jets snapbacks, jerseys. Phoenix Coyotes hockey jerseys and so on.