It all needs to begin with a passion for something. While it is true that there are many people who love to simply put businesses together and then sell them, that isn't the usual course of events. If you have something that you do well, whether it is building handmade furniture or website design, doing it as your own business can be infinitely rewarding.
If you think that having your own business means everyone else works while you sit back as some kind of "fat cat" collecting the cash, guess again. For most small business owners a sixty hour week is a slow week. If you don't love what you do when you run your own company, it will fail because you won't be willing to do the hard work to grow it.
While doing what you love to do is wonderful, it is hard to make a success of it if nobody knows that you are in business. That's why a well thought out marketing plan will always be needed with any new business venture. So before you launch your business, make sure you have a scrutinized marketing plan in place for maximum business exposure.