I myself love going to clubs and bars and prefer night game to day game! I also remember the days of Uni and wish I had taken advantage more!
First thing I would say to remember is have fun! Seriously don't take yourself or the game to seriously.. enjoy your friends company, have a laugh and smile and show that your having a good time! Girls will see and feel that you are a positive and fun guy!
When it comes to dancing don't hang around the dance floor staring at the girls like many men do because its creepy and it shows that you aren't fun your just there to go and try and perve on girls. Go and dance, get in the middle of the dancefloor and enjoy the music and the girls will flock to you. Trust me... you will notice girls edging towards you because they want attention and they want to dance with guys.
Hanging around at the bar is ok but you will notice most girls will go get a drink and then straight back to the dancefloor.. so what I would say is go to the bar when you want a drink and if a girl is next to you just strike up conversation.. one of my favourites is when I see one of these strange bright coloured cocktails girls get is I ask them what it is and joke it looks like petrol or something. Most of the time the girls will offer me their straw and I will take a sip and joke around that its a girly drink and they should drink beer blah blah. Then just add some kino and when you end up on the dancefloor and they are there you will most likely be able to go in and dance with them alot easier!
I wouldn't buy a girl a drink unless your on very good terms with her.. girls expect guys to buy them drinks and when i guy doesn't offer they wonder what they are doing wrong and then start to try and impress more!
This isn't really techniques or advice on opening but hopefully it will help with the image your portraying
I'm learning still as well and will be out clubbing tonight.. lets see if I follow my own advice ha!