You contact the potential user, explain who you are and what your trying to build, they like it and are comfortable signing an LoI. Thats pretty much it. If it

You contact the potential user, explain who you are and what your trying to build, they like it and are comfortable signing an LoI. Thats pretty much it. If its a big B and you need credentials, you'll need to get that first. You can do it by looking and sounding professional, bringing in advisors who add some weight, getting an intro from the CEO or owner (you'd be surprised how many will pay it forward). If its a small B just wander around and say hello. People generally want to help people who are making things that help them. And your not getting anywhere without understanding your user so you'll need to talk to them, emphasise. A lot of the earliest discussions will be more around you figuring out exactly how your product will help them.