You do business the same way you would in either company. A partnership involves two or more parties so let's rule that one out. The significant difference between a corporation and sole proprietorship is (1) cost to create, and (2) limited personal liability. I always advise my clients to set up a corporation. In almost all instances the limitation of personal liability is worth the value alone as well as the appearance, and sometimes necessity, with regard to clients. If you're just starting out and unsure whether to incorporate, you don't need to incorporate. But for a few hundred dollars, I think the benefits of setting up an LLC (Limited Liability Corporation) or an S Corporation for small businesses is well worthwhile. Good luck with your new business and let us know if you have other questions with regard to incorporation.