A Bill of Sale should only be used for "as-is" purchases, when payment in full will be made once the item is exchanged. It expressly disclaims any warranties that relate to the quality or fitness of the product.
Alternatively, many people are looking to sell items on behalf of charities at auction events. If you are are seeking donations for a charitable item, you should look into procuring a donation request letter. With this letter, as opposed to a bill of a sale, you can ask for contributions to your charitable cause while conducting an auction for a non-profit of your choice.
A Bill of Sale is used to protect both the seller and the purchaser in the case of any future issues. Since many purchases and sales between individuals are transacted using cash, it can be hard to prove that an item was received or paid for without proper documentation.
The next thing to remember is that your bill of sale template must specify the financial details of the transaction. Upon viewing the form, one should easily be able to tell how much the property was sold for and when it was sold. If there is sales tax involved, this should be noted as well; moreover, the method of payment (such as cash) should be clearly indicated in the template. Any bill of sale template, free or otherwise, ought to include these elements.