I am thinking when lease expires go to a month to month with all utilities paid by tenant.  

The option (or first right) still requires them to execute the purchase per the agreed upon price before the time expires on the option by using cash or financing with a bank, or they forfeit their right to buy.

I will always go out of my way to serve people and make sure that they are talking to the right people from day one, because I truly hate seeing lease option buyers lose option money if they don't buy before the option expires.

It sounds like you're using a system very similar to mine and I'll tell you exactly what I do Market for the motivated seller with expired listings cancel listings long days on the market landlords FSBOs and wholesalers. 

Buy a few feet along the property line from each neighbor IF possible.3) Search for High Days on Market MLS properties that are unusual for this market.4) Fixer Upper Search5) Recent Expired and Cancelled Listings6) Expired and Cancelled Listings from years ago that did not re-list7) Seller Financed properties8) Probate Sales9) Bad Foundation properties, Connect with a good Concrete Contractor10) Condo or Townhome with HOA litigation (close to being resolved)11) Properties where zoning can be changed12) FSBO and Make Me Move properties13) Find Duplexes that can be converted into SFR's IF they sell for considerably more locally.

You would need to consult with your local landlord tenant code.If they are not under lease or the lease is about to expire you could offer them a new lease that includes a deposit.  

That keeps your lease expirations at a time that works better and allows them to get a new roommate.

Or are you only using expired listings?

I have always done fixed term 1 year lease and I would like to try M2M.I have one tenant lease expiring and I am going to convert her to M2M.My current lease explicitly stated the lease cannot be renewed or extended without an signed written agreement between landlord and tenant, so I need some sort of a renewal/conversion agreement to switch to a M2M arrangement whereby both sides can terminate with a 30 day notice, but keeps the rest of the 1 year lease terms. 

In your situation I would work on creating capital and reducing expenses for the next year until your lease expires and learn more about the business.