The trick to hitting up a bar solo is to go to a place where there are at least 4 bars in close walking distance, although at least 6 is better, doesn't matter what kind of bars they are, don't shy away from "clubby" type places or sports bars. Hit up the most low key bar early, get started, and change bars at least once per hour until you find your fit. Also it is a necessity to wear something awesome/weird/cool. Feel the vibe of the bar and get into it. If someone strikes up a convo about anything, keep it going and progress into other lines of thought/conversation, even if it's as asinine as commenting on the bar and saying you've never been there before, or talking about how you're just bar hopping and trying to find cool people and some fun. Do those things and you will succeed. Once I'm hammered and in the correct bar at the right time I always end up at a table full of strangers. Or if you by chance see someone you know, GO WITH THEM. Follow the call of the party and make the night last forever.
If someone offers to sell you coke, say no. If they offer you free coke, say yes. If they offer you molly or Ecstasy, say yes whether it's free or not.