I'm not sure what I'd actually want a guy to do so the only advice I can give is what has happened to me in clubs and how I've ended up getting with guys, but confidence is definitely important and don't waste your time buying drinks, this is only worth doing if you can guarantee going home with them, though if we get more than one I will always alternate.
Anyway the guys who've tried it with me at clubs. One time I'd had to step back out of the way to let people walk through as was quite crowded and this one lad decided to stop and we just got chatting, from there before he took my hand and led me off elsewhere.
Another time I just walked up to this lad and started getting with him, to be fair I was pretty drunk that evening so don't really remember (and that's the only time I usually make the move).
One time I was sitting in one of the seating areas trying to find my mates and this guy came over and started chatting to me.
Another lad came over with a friend to our group and started chatting to us, came over to me and complemented me so got with him.
Another time my friends were boring me so I was just looking around to see what else was going on and caught the eye of this good looking guy and we just started dancing, not grinding or anything just dancing as I would with my mates and having a good time, which made a nice change.
Another time it was one of my mates I was out with friend who happened to have met up when out and didn't really talk to him or anything but somehow ended up getting with him.
Have also had the standard lads coming up behind me and trying it on, so I'll turn round and depending what they're like they might get my attention or if not I'll move to somewhere else within my group of friends away from them. Though sometimes they would just come and stand closer but no actual physical contact, leaving it up to me and then if I was interested I'd move closer to them instead.
So in short if you happen to be in a quieter area and are able to then do chat to them as I found I had a fair bit in common with a couple of them. If not looking around rather than focusing with the people you're out with will always give you more of a chance or if you can get them when they are away from the group they're out with. Though for me actually coming near to them will be enough to get my attention initially.
The only thing I've ever had happen to me that put me right off was standing in a queue at the bar with my friend and this lad came up next to us to his group of mates and then for some reason decided he was going to start trying to kiss at my neck and try and lick the side of my face, this was of course not appreciated and he got a good boot in the shins but didn't seem to stop him and only went away when he'd finally got his drinks. So don't try anything weird.