Drawing up a lease agreement help

[Allen Allcorn]

We have been using property management for 1 yr and our lease is up with them at end of July. I spoke with tenants and they are unhappy with the management team citing having to repeatedly call to get stuff done, I was unaware and now after talking with tenant decided we will self manage and save the money (10%) and headache the renters had. They are willing to sign minimum 18 month contract with us and are willing to do all minor maintenance/repairs themselves, I just pay for parts if necessary. It is a higher ranking military family and have been great tenants so far. It's a single family home. My question is what is the best way to draw up a lease? Get a lawyer to do it or is there a simple template somewhere? Also any certain non obvious things to include? Something a seasoned landlord might know of that we don't? This will be our first attempt at self manage and only have been invested in real estate for 1 year for our background.