My wife & i would like to pick up a guy in a nightclub/bar for a threesome whats the best way to do this & to attract a guy

I guess that depends on the type of threesome you're looking for. If you want the other guy to focus on your wife then the best way would probably be to have your wife hit on the other guy. If you want the other guy to focus on you or vice versa than you hit on the other guy. Just be cautious about getting punched in the face if he isn't into that.