Establish ownership rights to the work. Even in service situations, a product is sometimes the result of the work, so you should also include which party retains ownership rights. For example, the copywriter can state that she turns over all rights to the writing of the brochure to the customer and that she makes no claims of ownership to the writing once the customer pays for the written product. Add signature and date lines. Be sure to provide a space for each party to sign and date.
If you run a business as a sole proprietorship, it would be appropriate to be identified in the contract as John Jones doing business as Jones Plumbing. If you organized your business as a Limited Liability Company, identifying your participation in the contract by your name could remove any personal liability protection that an LLC provides. Similar issues can arise with a partnership if each individual is identified as a party to the contract.