L. A simple but sometimes overlooked item. Include language that allows the LOI to be signed in counter_parts. Again, this is a small item but it can save you days in the process. A Letter of Intent is a terrific tool for helping to get your transaction off to good start and moving it toward closing more efficiently. While the information above certainly isn't exhaustive, it provides a great platform. As stated above, always consult the proper professional before acting.
It is good to use an LOI to gauge the viability of purchasing the property based on the price an terms you are considering. IN other words, it is good to use to gauge whether or not the offer you have in mind is even going to come close to making sense to the seller.