A lease is the operating manual for the tenancy — and it's read carefully exactly twice: when something goes wrong, and in court. Write it for those two moments. A state-specific attorney-reviewed template beats anything downloaded generic, because landlord-tenant law varies enormously by state and city.
The clauses that do the work
Rent amount, due date, grace period, and late fee (where allowed) — precise, with the exact dollar figure. Term and what happens at the end: renewal, month-to-month conversion, or vacate. Security deposit amount and conditions. Who pays which utilities. Maintenance responsibilities split clearly: tenant handles filters and lightbulbs, you handle systems. Occupancy limits, pet terms, smoking, subletting/short-term-rental prohibition, and your right of entry with notice. If a dispute would touch it, the lease should answer it.
Common self-inflicted wounds
Verbal side agreements ("I told them they could paint") that contradict the document. Unenforceable clauses copied from another state — courts may strike them or worse, taint the lease. Vague language like "tenant maintains the yard" (mowing? trees? sprinkler repairs?). And unsigned or partially signed leases: every adult occupant signs, jointly and severally liable, before keys change hands.
Worked example
A $1,600/month lease says rent is due the 1st, late after the 5th, $75 late fee. Tenant pays on the 9th, twice. Because the terms are numeric and the delivery method documented, the fees ($150) stick and the paper trail is clean if nonpayment escalates. The neighboring landlord with "rent due promptly each month" collects nothing and starts an eviction on shaky footing.
When this rule of thumb breaks
The lease can't override law: rent-controlled jurisdictions, deposit caps, mandatory grace periods, and "repair and deduct" rights apply no matter what the document says. Month-to-month arrangements trade term security for flexibility — sometimes correct for a planned renovation or sale. And enforcement has judgment: strictly enforcing every clause against an excellent long-term tenant over trivia is how you turn an asset into a vacancy. The lease is your floor, not your personality.