owner financing instead of renting

[Michael Gerstner]

I love renting my properties, and am in the process of my first flip, seeing both advantages, they both have great profit potential, I have been thinking of some owner financing (me being the bank)  on some future purchases, seeing the benefit of a percentage down and interest on top of the mortgage payment with no land lording responsibilities. My question is where to start with the contract to protect me and my property, and what are some of the downsides of owner financing from anyone that has done this.