Where do your first B2B customers actually come from?

We're launching ScoutTide here on Tuesday, and building it made me curious how other small teams find their first customers.

Our bet is that the best leads are people who already said, in public, that they need something: a post asking "can anyone recommend a tool for X", or a public tender from a council or a development bank. Cold outreach to lists has worked less and less for us.

So, honest question: where did your first 10 paying customers come from? Cold email, communities, referrals, tenders, something else? And what did you try that didn't work at all?