i have found that it works walking up to a group amd starting the conversation by doing a proposition bet for example the 5 questions game this way you are there for a reason and can find out about the people during the game. the advantage of this is that even if you get shot down you still leave with a drink and the people will remember you. what do you guys think?

It is an empirical matter but principally dispositional. Such routines have been effective openers for me in the past but I disavowed that technique a while ago for one reason: it's just not me. I don't find such routines fun so I don't use them. If you find them fun, can execute them with confidence and charm then stick to it.
There are a lot of routines out there. It is all about calibrating to your tastes. For example, I'm a straight shooter. I don't like to procrastinate. Consequently I tend to be more direct. Also, I'm something of an irreverent iconoclast so I don't take the interaction all that seriously i.e. I am very playful. Since these traits come naturally to me it is more effective if I play to my strengths.
In short, if it works for you and you feel good about it do it.