State that, no binding contract is to come into effect, except to the extent set out in the letter and that neither the letter nor any work done or payment made under the letter shall be deemed to be a waiver of the requirement to provide a binding contract. Finally, every effort should be made to finalise the contract as soon as reasonably practicable after the letter of intent has been signed.
Corporations and many other businesses can use this type of letter as a precursor to a formal agreement. In it they can list the salient points of their intentions and what they intend to include in formal contractual agreement if both parties can come to an amicable agreement. Thus it can be used as a fall back document should any questions arise during the final contract negotiations. A good example of this might be a letter sent to a company's investor explaining their intentions to buyout another company and what it is expected to do to the value of their stocks.