Lease suggestions needed

[Victor Trujillo]

After acquiring my first 4-unit rental property, I will be self-managing it. I understand that an important part of property management is having a rock solid lease. With that being said I've got three questions for you:

1) Should leases be 1 month long for say, 4-6 months? Then after they've proved they're a suitable tenant, offer up to a 6 or 12 month lease?

2) What have been your biggest mistakes with leases?

3) What are the most important things to include in a lease?

Feel free to link examples of your own leases, if possible! 

I appreciate your time.