How to avoid hiring a "nightmare" candidate

A dream is a beautiful thing. A nightmare is something to be frowned at. So, if you're hiring somebody, wouldn't it be nice to avoid nightmare candidates? What is your strategy for new hires?

If you don't have a specific strategy when hiring new candidates, then you may be doomed to oppression for your company ( a real nightmare). So, I have a few ways to manage the atrocities of this process.

1. It's all about how the candidate sells you in the interview.
   
   It's fine to be the smart one that knows the company in and out. But, if you're hiring for a well-known company, this might be a bit negative or could be a nightmare if they don't know anything else (and was just faking it).
   
   Let's say you're one of the HRs for Facebook...tons of people know all about Facebook. But, who knows anything about the engineering of Facebook? Developers. Not just the employee developers, but actual app developers who use the Facebook Developers network. Who else? Someone may know a lot about Facebook, but what ELSE do they know? Grassroots marketing? Organic SEO?
   
   Scope not only knowledge the candidate has of the company, but ask lots of questions (if needed). You want to make sure that they have more than just basic knowledge of the company. What they need is tact & skill. Remember this!
2. Ask for some humor or a joke in the job ad.
   
   It's a drag, admit it: To read resumes/CVs/cover letters is a big drag. Most career documents are boring, similar, and rarely tells you much about the candidate.
   
   If you require the joke/humor, and someone doesn't do it - you'll know right away they don't read carefully or weren't patient enough to do it. You could eliminate half or so of resumes/CVs, if this were the case.
   
   Look at the bright side, if you get a good laugh, at least you'll know your candidate has a good sense of humor. Usually, with a good sense of humor, comes good communication skills and a sense of self-worth. However, don't depend on this objective view.
   
   Also, look for inappropriate jokes and eliminate those. These ones represent a bad self-image or a bad view of the world - thus your candidate might be a nightmare to have to deal with (from problems with harassing behavior to inappropriate attitudes). You want clean, focused customers. If you don't feel like you can have lunch with them, then don't bother.
3. Tell people why they don't want to work for you.
   
   Shifting people's focus from "why you should work for us" to "why you shouldn't or don't want to work for us" is a great way to eliminate those overjoyed candidates, whom after the job excitement wears off, they fall lazy.
   
   You want people with a steady, low excitement and high productivity rate. So, make sure to include what you don't want in an employee in your job ad. You will get some good candidates, who're not all about the excitement and not about the work.
   
   A lot of perks are nice, yes. But, having too much is just going to flood your inbox with wishful people, rather than productive people. Productive people don't super-seek after perks. Instead, they seek after places that have good, lengthy projects with an awesome bonus (for finishing early, getting good brownie points, etc.).
   
   Many times finding that right candidate is like finding the right mate. It's better to know yourself well and talk about your faults up front, since they'll find out sooner or later. Make sure to establish a company value on positivity and growth, and talk about what you don't want to be involved.

Overall, don't seek after employees you have a bad gut feeling about (which can be a nightmare). Only choose those that you'd enjoy lunch with.

Comment with your tips or suggestions. We appreciate it!