There are a few places where angel investors tend to find great ideas to invest in. One such place is online startup databases. Startups typically list themselves on these databases in order to gain exposure to potential investors. Another place where angel investors may find great ideas is through referrals from existing portfolio companies. If an angel investor is investing in a company that they're already familiar with and they're happy with the company's progress, they may be more likely to invest in another company that the portfolio company recommends. Finally, many angel investors also attend startup events, such as pitching competitions, in order to find new and interesting companies to invest in.