Ask HN: How do you hire people?

We're a small company looking for a killer JS dev, to build a node-webkit app for us. As we're a small team and we're on kind of a budget we're focusing on the slightly lower end of the 'top' candidates and trying to focus on people who have killer aptitude.

The position is paying up to 50k, it's just outside of London (UK) so we think its a fair price, however, the CV's we've been getting though they read well when we get the candidates in the room they are beyond useless, can't even answer simple JS questions!

So I want to know, How do you guys hire? What's your process?

Also, where do you look? Agencies have sent us these guys and I'd surprised if any of them can tie their shoes let along code a mapping application :(