I added links below to cover your interests in SFH and small multifamily units.https://www.biggerpockets.com/renewsblog/2015/05/26/real-estate-financing/ (RE financing)https://www.biggerpockets.com/renewsblog/2015/03/27/financing-options-rental-property-guide/ (financing options for rentals)https://www.biggerpockets.com/renewsblog/2014/03/06/bp-podcast-060-serge-shukhat/ (0-68 rentals in 4 years) https://www.biggerpockets.com/renewsblog/2014/08/02/passive-real-estate-investing/ (slowly building wealth through passive investing)https://www.biggerpockets.com/renewsblog/2015/09/30/bought-rehabbed-rented-refinanced-14-properties/ (BRRRR explained)http://www.biggerpockets.com/renewsblog/2013/01/04/how-to-rent-your-house/ (house rental guide)http://www.biggerpockets.com/renewsblog/2013/02/22/buying-rental-property/ (how to buy a rental property)https://www.biggerpockets.com/renewsblog/2016/01/13/top-8-real-estate-calculations/ (real estate calculations)https://www.biggerpockets.com/renewsblog/2014/03/13/investing-multifamily-ben-leybovich/ (Podcast 061 - How to succeed in multifamily investing) https://www.biggerpockets.com/renewsblog/2013/04/09/how-to-buy-a-small-multifamily-property/ (How to buy a small multifamily property)To be more successful, you simply have to work on the other elements to progress your REI pursuit.

You don't have to store tenant belongings (with a couple of exceptions and that's only 7 days.) 

Home ownership is at 63% the lowest level since 1965.Rental vacancies fall to 6.8% the lowest level since the 1980sWal Mart closes 269 stores in 2016Macy closes 40 stores in 2016K Mart closes an undisclosed number of stores in 2016Dow plunges 450 points today so far.What does that tell you?

I was thinking of creating a rewards card, where I go to different stores and get a discount for my tenants when they use my card.  

Thanks for the input @Penny Clark and @Kevin Manz I did purchase 40 gift cards to the grocery store.

That would be adverse possession, however failure to maintain and improve would eliminate one of the (5) key elements required for prove up. 

The Bigger Pockets book store if full of great books: https://www.biggerpockets.com/store

I manage everything using it and no longer store receipts in paper form (upload to TenantCloud).  

The Bigger Pockets book store if full of great books: https://www.biggerpockets.com/store

It get's you into the investor mindset which I think is a crucial element for being successful in this business.