Converting (especially on a project-by-project basis) is a process, not a one-size-fits-all. So, my top advice comes in two parts:
1) Know yourself. What you WILL do, what you WON'T do, and the price at which you will do your thing.
If a potential Buyer approach me, I first make sure that they're actually in the right place (no point trying to convert someone who's looking for tacos when they walked into a pizza place), that I can fulfil what I'm looking for (no, we cannot put pickles on your pizza, we don't stock those), that they have the budget (no, the pizza isn't free), that I'm okay with what they're looking for (no, we WILL NOT put harmful stuff on the pizza, not even as a joke), and that I can work with the Buyer (no shirt, no shoes, no service). If the project seems like a good fit, well, half the process is already done.
2) Know your customers. Who and where they ARE, and who and where they are NOT.
If I'm looking for Buyers out in the wild, I first understand my buyer persona, my target market, because it's (again) pointless to try to convert someone who has zero interest in what I offer. I recently saw the (particularly clever) "Clustomers" marketing campaign put out by Intuit Mailchimp that sums it up rather nicely.