Ideally you can acquire the necessary skillset(s) by offering an appreciable chunk of equity. This always involves some networking. Keep in mind that all startups are a gambit, and no one if doing anything "for free" if they're granted equity, but it can be difficult to find people with a like level of risk-aversion. And you're right, IME if there is not a lot of traction and interesting work to do, people will start wondering if their equity is worth their time.