It is important to have your financing in order prior to writing your offer.  You and your lender can discuss various ways of financing, including the interest rate best suited to you.  You should decide on a specific type of financing and disclose that in the offer.  Some sellers will only accept certain types of financing.  Should you decide on an FHA or VA, a certain amount of accountability is placed on the seller, which includes extra costs to that seller.

Another important item is a pre-approval letter from your lender.  This is an excellent way to let the seller know you have your financing in place.