You will need to negotiate how much of the lease payment goes towards the purchase price when you decide to exercise the option.

There are some great deals on the northeast side, but in general, areas like Converse and for the most part, east of I-35 are starting to experience higher crime rates, which means that caution should be exercised. 

The option should be written so the option provides the buyer, or s/he's assigns, the irrevocable right to exercise s/he's purchase option as per terms negotiated in the option.The option to purchase is atypically negotiated with a fixed price, or a price escalating over time, or a price tied to the market e.g. appraised value x Y% (+/- 90-100%).Oh, and if you're the broker in the deal make sure the broker(s) and sale commission are exclusively identified in the option paragraph. 

Better to think of this as a snowballing exercise.  

Some things you might want to include:Have a notification date to exercise the options, for example 30 or 60 days before the end of the lease.You can put the rent prices in the contract or something that says, "95% of the current market rate, but in no event will the rent payments be less than the last month before the option is exercised."

A successful investor exercises discipline and doesn't acquire when conditions are unsupportive. 

The difference between an okay cash flow versus great cash flow on my first 1 or 2 properties has a domino effect on the true compounding of interest in the larger plan over 10 years, so I have to exercise considerable restraint.

That serves several purposes: (1) It will a allow you time at your new job so if you decide to get a mortgage and exercise your option to buy, you will have 3+ years on the job and (2) during your lease period, you will have the opportunity to make sure that the market is going in the direction you want.

It's tied to the property which secures the loan.If you deed the property into an entity, you run the risk of the lender exercising their rights under "Due on Sale".If you can manage it, have the LLC buy it from you.If not, check with your legal counsel about deeding it into a trust.

If nothing else, this exercise is worthwhile to do so that you can figure out the pieces of what really makes a good deal.The bottom line question you need to ask yourself is "How do I plan to profit on this deal?"