Tell them to leave the toilet seat down for you - equal rights and all.
Also, make sure they keep their boyfriend problems private, or else you will go mad after a short while. Nagging and bitching gets to everyone after a while.
The hair in the plughole won't be a problem with your own shower, so that's a good thing.
Them playing crap, sentimental music loudly at 2am might be a problem.
Get in on as many of the meals as possible. The two girls I lived with once made food every night because they loved it. I paid my share of the purchase costs ofc. Do the same.
Apart from that, just try and enjoy it as much as you can, and make sure you bone at least one of them on the rebound :thup: That will create a great atmosphere amongst the other girls