My niece is a student, shares a house with half a dozen others.
Last year, one of the housemates was given a collection of cocktail items and ingredients and they had a great cocktail evening and my niece raved about it. Was trying to think of something similar for her forthcoming birthday but not cocktails, and not gin as she doesn't like it.
Fall back would be a few bottles of Prosecco and nibbles for pre-drinks before they head off clubbing.
But the genius minds of MN can no doubt come up with something a bit more interesting. Budget £40 ish