Household items. Unless your place is furnished, you'll have to fill it. "It's best for each roommate to purchase [items] outright," McGregor suggests. "So when you inevitably split up, there's no fights over who owns what."
And if something breaks or is damaged, consider that just part of rooming with a roommate, McGregor says.
Figure out the rules beforehand. It's not as easy as it sounds. Earlier this month, the U.S. Supreme Court heard arguments about whether police can search an apartment if one resident says "no" and leaves the home, but another roommate says "yes."
So the more issues you can discuss, the better, from your morning and night routines to cleaning rituals. "Without a formal agreement – written or verbal – even with a family member, you're leaving yourself open to disaster," says LinDee Rochelle, 65, of San Diego. She lived for three years with her "adult, video-game playing son," several months with a friend's 55-year-old son and now lives with two cousins.
Hope Rising, a 48-year-old paralegal in Clearwater, Fla., echoes that it's smart to discuss rules beforehand and observes that it helps if roommates are as compatible as if they were married.
"I live with my ex-sister-in-law," says Rising, who has shared an apartment with the woman for eight months. The two have considered renting a house together, but Rising says she now isn't sure. She conjures up an image of Felix and Oscar in "The Odd Couple" when she describes the differences in how they view lights, air-conditioning and food.
"I turn lights off when I leave a room, keep the air conditioning set at a reasonable temperature to keep it from running constantly, eat healthy [and] put caps back on things," Rising says. "Because we split expenses, these are major issues between us."
But Rising should take heart. Good things can come from even the worst of roommate relationships. As much as Rahim struggled in the aftermath of his roommate's departure, when he was around, he at least got a great deal on a pair of sneakers and two jackets.