....Let's just say, they've already called in enough service calls for problems that literally equated to changing the battery in the thermostat.....

One thing I would emphasize is to SCREEN your tenant - if you wait a little longer to make sure that you have a good tenant with landlords who liked them (not just a positive review from their current landlord) and solid financials (credit score, monthly income) you're likely to be much happier in the long run.The type of tenant will have a big impact on your land lording experience: are you replacing the occasional smoke detector battery, or do you have to repair gouges in walls, fix water damage, and repair flooring at move out.  

I put in my lease that anything under $15 is the duty of the tenant and used the specific examples of detector batteries and light bulbs :)

The tenants sign paperwork at lease signing stating that all smoke detectors etc worked at time of lease signing and they are responsible for checks and battery replacement.  

@Tingjun Lei I would put a cage around it, and I would install fake cameras with battery operated blinking red lights at the doors and above the outdoor condenser to at least make it look like you have a camera.  

It usally flush the bottom feeders out and allows me to recondition the vacant aparments.

Painting countertops is a good way to recondition for not much money.

I would not be doing it to make extra money, I would do it to avoid constant phone calls about unclogging a toilet, changing batteries in smoke detectors, changing lightbulbs, small things like that.I have seen this suggestion in other posts on BP.

With regards to real estate investing, TESLA is building a very large (second largest building by square feet in the world) to build the car batteries for mass production.

You hate to send someone to fix the heat to find out the tenant doesn't know how to change the battery on the thermostat.... but that is the risk you take.