We've upgraded some of the furniture and furnishings in the home.

I recently, a few days, upgraded to pro after a webinar I watched.

We plan to purchase and potentially upgrade the unit that we plan to rent out to attract more rent prior to renting it out.

Any creative upgrades? 

@Jeremy Lee  I would wait on the upgrades until you are going to sell the home. 

I put in about $40k in upgrading two of the units and a foundation repair and now it rents for $4,590/month.

You'll need to upgrade to a minimum 100amp service and I suggest going up to 200amp as there is often less headache with inspectors and it will cover any additional electrical needs in the future that may arise.

Making extra payments is always a good idea when you have a higher interest rate, that allows you to use the money you would have put down for some upgrades or needed work.

That is the time to do repairs and upgrades to get the the unit rent ready again.   

If the market maxes out at a certain rent with standard fixtures and finishes and no washer and dryer for example, it does not make sense to upgrade units to premium level and add washer and dryer if you can't increase the income and ultimately the value.