It depends on your market. But if you try to build a company, I assume that you want to solve a problem. If you solve a B2C problem: talk to friends affected

It depends on your market. But if you try to build a company, I assume that you want to solve a problem. If you solve a B2C problem: talk to friends affected by the problem, or launch a Meetup based on this problem. You'll get free feedbacks and people LOVE to talk about themselves. If you solve a B2B problem: talk to friendly businesses affected by the problem, or go to events and conferences as a vendor with kakemonos talking about the problem you solve. If the problem you solve is really important, you'll get plenty of people coming to your stand to talk to you. Once you'll have a few "leads", you will be able to refine the market segments that are the most affected by the problem you solve. THIS is really important: for B2C, you'll have to target this segment in your future ads, for B2B, you'll have to target this segment in leads generation. Also: - "Should I try to approach bosses or common workers of companies?" => Talk to the guy affected by the problem you solve. It might be the CEO, or a manager, or the worker. - "Should I phone them, ask for an appointment, explain my goals and if they let me in, do the talk?" => Yes, phone is better than cold email. But be prepared, it's really harder than cold email. - "What is the right approach to talk to my potential customers?" => Beginner script: Hi, my name is X, I represent Y, we solve THE_PROBLEM_YOU_SOLVE. Are you affected by this problem? Could we talk about this in person at your office?