Earning extra money through a side business has become quite mainstream these days. If you want to become an entrepreneur, starting a side business is a great way to get started. It also lets you pursue a hobby productively and offers you an opportunity to try something apart from the nine-to-five job. Here are some of the best side hustle ideas you can do on top of a day job. 1. Creating and Marketing Online Courses If you consider yourself an expert in any subject, you can create online courses on that and sell them to interested parties. It’ll not only be a source of side income, but also let…