I did not go to my prom and therefore did not attend my afterprom. However, I did attend my girlfriend's prom and afterprom and it was a lot of fun. Unfortunately, the kind of fun it was can only be found from one source:

Me.

I wore streamers on my head the entire time and shouted loud things at random people, asking them who they were and why they were where they were. I also told random people I did not know that random people I also did not know were currently looking for them and seemed concerned because they could not find them. I also told jokes and spilled some poor girl's tea (I made it up to her by bringing her a cup of tea the next time I saw her, she thought it was very amusing and sweet).

Anyway, good luck with your after prom. I won't be there so you'll need it.