I will tell you my favorite hiring trick, by far. Before I do, though, I'll set the scene. I was looking for a new gig a few years back. I was mostly happy at my job, doing interesting stuff, not killing myself, and making good money, but itching to do something new. Wanted to get in the startup scene, etc. So I see a new company's job posting, and it looks like a perfect fit (location, mission, everything). I meet with the CEO, have a few conversations with investors and employees, and things are looking good. Then they throw me a curve ball - "We want you to do something interesting with our product." - I spent the next two weeks working my ass off nights and weekends. Mind you, not compromising my full time position in any way. In the end, I did something interesting, and it turned out to be a great thing for the company. More importantly, it let me get to know their product deeply, and I understood the kind of environment I'd be entering.
The moral of that story - when hiring, challenge people to do something for you. Give them a week to work with you. Pay them even. Just see how they actually work. It'll work well for you, and them - even if your rate of hiring is lower than you'd like.