Dress better.
If I dress OK I can get with 7-7.5s
If I dress my best I can get the top tier.
Also look for signals. Could be as obvious as a girl asking me if I want some gum while dancing with her (lol, this happened recently in Vegas) or eye-contact, brushing against you and being in close proximity.
Proximity is a big one.
But more than anything, I don't second guess signals. I trust my gut. If a girl seems down, I go for it, whether I'm right or wrong.