New flooring throughout, painted the walls, trim, ceilings, re-piped, closed in the water heater and furnace to make a more appealing mud room space, painted the cabinets, new hardware on the cabinets, new dishwasher.

Be careful not to get lured in by cheap, low end properties in undesirable areas however.

There are some great neighborhoods in League City that do not have MUD districts and keep the rates lower. 

Well one day as I was applying mud on the drywall, a light bulb went off in my head.

Yep, clear as mud...And, I actually met the person who wrote the modern-day ("simplied") tax code.

They tend to be booked out for most of the winter (for skiing/winter sports), empty through the spring/early summer, pick up before the end of summer/fall when the leaves are changing, and dead during the mud season before winter.

Tenant did not put mud under backerboard correctly, poorly grouted tile, unclogged a bathtub by driving holes into the P trap and having it drain to crawl space, poor painting, etc. 

That should be about as clear as mud!

I might leave some paint, drywall mud, or various supplies that really wouldn't be that exciting for somebody looking to make a quick buck. 

Maximize tenant rent by adopting dynamic pricing; reduce tenant turnover by upgrading, immediate respond to requests, retraining personnel to be tenant responsive and tenant friendly; eliminate undesirable tenants; upgrade property physically and cosmetically; convert from utilities paid to separately metered; evaluate prices paid for insurance, taxes, garbage, water, security, landscaping.