The market you are in is critically important.

Know how to take constructive criticism.

How effective were you with critical tasks?

@Zack Dasbur  While you can't sign away liability you could put in  the lease that they property has an elevator and they are responsible for proper use, attach the critical points to the lease on use and also cover elevator related charges. 

As such, the carrying costs need to be considered.This is why it is critical to have a good grasp of the local market.

I think too many times people try to do things themselves to save money or cut corners when they should just hire a professional and focus on their operations and things they do well or that are critical to generating revenue.  

I'm not criticizing - I have no way of knowing.

If you are active with your investing, having access to the MLS is critical. 

There are many reasons for my belief but some are It leverages your local knowledge baseYou can be your own PM saving money that is critical when starting out.You can do some of the tasks yourself saving money.You do not need to build a remote trusted team, instead build the local trusted team where it is easier to provide oversight.You can house hack if you choose.Good luck

Mapping this out with the right loan officer (who understands all the angles that matter to real estate investors) before you get started is absolutely critical to your success.