Be sure to save all your receipts even for something like toilet paper. If an item is used in the operation of your business, it is considered a business expense. A company that specializes in a particular service such as computer repair doesn't have much need for supplies beyond what can be picked up at a hardware or computer store. A company that specializes in marketing a product in packaged form does. So, you've decided you love to cook and want to market Grandma's fudge.
Any food product takes a little more consideration and planning for.
You'll need to be able to list the ingredients of your recipe, know the amounts required, then contact a company that will nutritionally itemize your product. Typically, they also provide sterilized packaging, but in case they don't, you'll need to contact a company that does. Non-food products don't necessitate as much attention paid to health statutes. Whether making homemade soap, candles, teddy bears from old quilts, or purses from old license plates concentration should be on the quality of product and uniqueness of packaging. Once you have a finished product to sell, you'll need to contact buyers.