Most of us have heard the story of a intelligent person tinkering in his garage and a decade later have a multi-million dollar business with warehouses and employees. These are outliers that don't often happen but they can happen when all the right steps are taken. There is an essential difference between those who will succeed and those who don't.
Entrepreneurs must have the right product. Yes, really smart people can find many products but if your selling something no one wants and there is no market demand for it you will be fighting uphill. Large companies have often blocked out entry into certain markets and to be successful means offering something unique that the market needs.
There is also a level of unwavering commitment. You can't quit or give up. Make sure you continue to work on it everyday even if it is only a little bit. If you leave your hobby business for a while turn around and pick it back up again. Over time you will learn, develop and find new ways of doing business. It could take you a long time but it will eventually get there.
Once you do start to sell products there is a high probability that copying the same method over and over will provide you with a solid start to regular profits. What worked in the beginning tells you something about how to approach the market. Don't stop there though, you will want to develop your method to save money, improve quality, and cut out unnecessary steps that don't add value.
The right product, learning commitment, and a basic process are are not enough. To be really successful means to create economies of scale. Entrepreneurs can turn their business from a hobby into an industry by buying in bulk, improving production speed, and keeping prices competitive with other large manufacturers.