I would look at the amount of rent you are able to get, deduct property management fees, mortgage interest, taxes, insurance, an estimate for repairs and upgrades over time, and then make sure the number you are left with is still positive. 

After a few years of marriage, we refinanced it to a 15-year mortgage and moved to another house (upgrade).

It's a great opportunity to upgrade a unit and get those rents up to market value!

Is there anything more than a letter or notice telling my tenant of these upgrades, dates, and any disruptions or outage periods with utilities (Electric for a few hours i'm assuming) that I need to do. 

@Vincent FranzeseIf you do not want to pay the monthly fee, just buy the Quickbooks physical software for a one-time cost (you will need to upgrade every few years).

We have been roommates for years and just upgraded to a property that I purchased and now they are paying the rent to me instead of a landlord.

Have extensive resume and projects completed.Am currently finding projects in DFW that others are missing as we understand how to re-design/re-work/extend/upgrade and do the work etc (not flip) to release significant equity. 

If you have good paying tenants in place you can ask them if they prefer unit upgrades for an added cost.

Beyond upgrades, have others learned to have a perceptible influence over appraisal outcomes particularly during cash out refinances? 

I did some repairs and I hired a few tradesmen (handyman, electrician, plumber, etc.) to fix the place up as it needed some repairs/upgrades because the two prior property managers did not take care of the place and the owner was living out of state.