What in my lease should I make sure to have that might not be in generic leases?
Leases require knowledge of the law and experience as the Landlord. I could give you a lot of ideas, but they may not match your laws and you may not have the experience/policies to enforce them.
My recommendation is that you purchase the BiggerPockets Lease Agreement Package under Tools. It's written by and for investors and is attorney approved for each state. Use it for a few years and adjust it as needed.