Don't move in with friends
Don't move in with a relationship partner until you've been together enough to know without a doubt that you're compatible with each other, and you've spent days in each other's company and already know each other's quirky habits and the extent of them.
Always pay for your own stuff. Never enter a communal arrangement where everyone is buying something for everyone else. With things where it's unavoidable, like toilet paper, take turns. Be responsible and keep a roll or two as an emergency supply in case they neglect their responsibilities, and don't tell them you have it so they'll learn their lesson. Otherwise buy what you use and use what you bought. Otherwise you're bound to get into arguments over it.
Simple reason is, **** changes when you live with someone. It's not like when you just see them when they want you to see them, or when they agree to let you see them.
You're going to see them everyday, and a lot of the time, most of the day. Whether they're happy, pissed off, upset, depressed, bored, anxious, frustrated... You're gonna be around for all of it, and you're going to have a hard time avoiding each other. And that's when you start to learn that everyone in the world, no matter how cool they seemed to you usually, can become pretty damn annoying with only a few days of actually living with them...
My roommate chants and meditates for a good hour or two every day, and then he does more chanting in the shower for nearly an hour... Guy's got all these little chimes that he dings to "synchronize his cells with the vibrations of the sound". Sits there looking out the windows contemplating "What could that tree be thinking about?". Leaves glasses of water full of gem stones all around the house to absorb the negative energies. Likes to sit there telling me about the frequency of love, and how people need to learn to tune their molecular and cellular rhythm to that frequency. Babbling about quantum physics he doesn't understand, and biology I learned in highschool as if it was some deep scientific stuff.
As far as I'm concerned, he's a total nut job, believes a load of ********, quite frankly insults me with his attempts to explain it scientifically, and he can be annoying as hell.
But he pays his rent, so I'm fine with that... I have my own space, with a lock on the door, that he NEVER enters. I have a good set of ear phones so I don't have to listen to him, and I have everything I need in my room except for food and water... For the most part, he keeps to his own room as well. It works because we have no previous acquaintance with each other so there were absolutely no hard feelings when I put a lock on my door and sat in there all day listening to music. Otherwise, I just have to smile, be civil, and keep my thoughts to myself on the rare occasion that we speak to each other.