What @Todd Plambeck said, except also wanted to add that for master bedrooms, I pick up clearance black-out curtains, nice quality machine-washable fabric, neutral styles, with the white backing (for usual HOA requirements) and on-sale hardware and install them myself.  

I also use semigloss throughout because it is washable, so I don't have to paint often.If it's dirty, grout sponge and Krud Kutter or other degreasers cut through the dirt and leave a decent looking paint surface.I actually haven't painted in 7 years, I think.for college kids, definitely use semigloss

Even if you buy a sofa with washable covers, you may not have time to wash one in between guests.

Set them up so they are easy to turn over -- Allure floors, standard washable semi gloss paint, month to month rental agreements so it is easy to get rid of non-payers (if that is true in your area), and clear instructions to tenants on what they need to do to get SD returned. 

Those rugs I mentioned are washable, which makes sense to me at my beach side property.  

Mold on paint is easily washable.  

The time you save using a good quality paint, that will be washable and hold its color for touch ups down the road, is worth the extra cost.  

Even a basic Low-Sheen or Satin finish will offer decent wash-ability. 

Are you a cheap landlord who uses  flat non washable paint?

The walls aren't very washable but you can literally repaint a room for a few bucks.