When people are looking to start a business, I always suggest they find a way to make money doing something they love, or selling something something they love. Recently I met a woman who found her best way to invest 20000 was to start up her own jewelry company.
It was not as hard as you might think. When she first started out, she was not sure if she should sell exclusively online or focus on opening a store front. I advised her to start with online sales. It takes a much smaller initial investment as she only had to focus on buying merchandise, and not securing a lease and buying the furniture necessary to run a successful store front. It's also a great way to get an idea of the potential market before committing to a store front.
She found a wholesale company who offered really nice jewelry sets for much less than retail value. With her initial 20000 she was able to buy 100 sets that she easily sold for double her money within a month. She was then able to take those proceeds and invest in even more inventory.
After a few months of making huge profits she determined she would, after all, like to have a store front. With the returns she'd made on her initial investment she was able to open a very nice high end boutique jewelry store. She still sells online as well but is able to interact with her customers in her store. She'd had such a great time – and made a ton of money!