For me, I've just built it over time. I keep a recommended vendor list for my team to work off of. I usually start by reaching out because I need something. If they are bad at communicating, then I don't do anything with them. If they communicate well I'll give them a shot at how the job or referral went. If I referred them, I follow up with the person I referred them to and see how it went. After that I'll add them to my vendor list. I've found having really solid folks around you can strengthen your brand but just like finding employees, you have to slow roll it to maintain your reputation.
