Depending on what you're building, see if you can turn a customer into an advisor. For a product I once put together for other businesses, one of the earliest

Depending on what you're building, see if you can turn a customer into an advisor. For a product I once put together for other businesses, one of the earliest users ended up being very helpful as an informal advisor: giving feedback on the app, introducing me to other folks who'd potentially be interested in using it, and giving me insight on that field because I had none. I've found that if you have someone on your hands who was one of the first people to use your product and they were especially enthusiastic about it, they'd be happy to serve in that role (even if just informally).