Colby,

Speaking from experience and as a landlord, I would be livid if you
followed Tom's advice and sanded my floors.

I wouldn't dream of making any modifications to a rental without consulting
the landlord. That could lead to many unwanted problems!

However, back when we rented, I often asked our landlord if we could make
improvements. I can't remember a single time he was against it. In many
cases, he would even buy the materials, and we were essentially free labor.
We landscaped the front and side yards, repaired damage from previous
owners and repainted the walls, fixed plumbing problems, repaired the
appliances, etc. We got a better place to live, and he got an improved
rental without having to pay someone to fix things. When the time came to
move, he practically begged us to stay...

I'm sure it depends on the landlord and how long you plan to live there,
but it couldn't hurt to ask the landlord if you want to make improvements.
You might be surprised...

Anthony