Just about anything that you find appealing can be the basis for a home based business - as long as it's also likely to be appealing to some future customers. Don't let anyone convince you that you never have to make a profit and pay taxes on that profit. If your business resembles a hobby, the IRS will try to argue that you can't deduct any losses from a hobby and that you have to pay taxes on any profits. There is a tax break available where you can deduct your losses for two of any five years if you make a profit in the other three years. (The "hoby loss rule) And, the home office deduction is limited to the profit from your business each year. (Excess deductions can be carried over to future tax years.)
Nearly any kind of marketing based venture where you are trying to sell some product will qualify as a home based business if you operate from your home. While I personally have an aversion to Multi-Level Marketing plans, there are a lot of people who do make a very nice income from such ventures. If you have any expertise in any subject, you can offer consulting services about that subject or you can attempt to sell your know-how through a newsletter. Perhaps you have some skill with a particular software program. You could offer advice for a fee over the phone or you could do contract work for a company that needs some temporary help. You could also work as a free lance writer or an editor for companies that have large web sites. You could create an email publication or a web site and then sell advertising to help pay for the time and cost of providing that information. If you are moderately skilled at maintaining a web site, there are a host of "affiliate" marketing deals available through the Internet. Basically, you promote someone else's product from your web site and they pay you a commission for anyone that comes from your web site to theirs and makes a purchase. You could set up a web site to sell books through Amazon.com or other book dealers. Being able to deduct some of your home expenses for a business office in your home is a mixed blessing. As long as you own the home, it provides some extra tax savings without having to incur added cash expenses. Actually, a home office is usually much less costly than an office outside the home, so you are also saving money by having an office at home. The other side of the issue is that when you sell the home, part of your sales proceeds will be subject to depreciation recapture and taxed at a rate of 25% -- whereas the gain on the non-business part of your home may be completely tax free up to $250,000 per spouse. Another "catch" is that you must have some profit from your home based business in order to claim this deduction.