One of the hardest things about being a business owner, solopreneur or entrepreneur is hiring. At least that's been my experience! Some great advice I heard once (I think it was on Chris Ducker's New Business Podcast) was to hire slow and fire fast.
With that in mind I've created a system of sorts for my new hires. They go through a six week internship program and work for free while we sort out the kinks and get them on track.
After the six weeks if they make the cut I bring them on board.
It's working out so far, the interns love the opportunity and all my new clients from here on in will be written by the interns. It helps me scale my business and helps them to learn a new skill while earning a little money.
And that's my first suggestion for you when hiring someone: hire slowly! Set up a competition for interns for a few weeks. Make sure they learn something no matter what but also be sure they are the right fit for you and what you're doing. For me it's incredibly important that they can write and they can implement edits I give them the next time around.
Or if you must hire someone straightaway be sure to take them to dinner, have a drink with them and figure out if you all are a match. Ask yourself if you'd want them in your home for a meal - if you say yes then hire them. If you aren't sure they probably won't work out.
My second suggestion for you is when you actually write the ad. Do you need a detail-oriented person? If so add a little detail in your ad, something that the person must mention in their response to you.
For example, I had many people apply for an internship but they wouldn't read the whole ad and understand the six week training program.
So I included a sentence in my ad that says in order to be considered they must mention the six weeks in their response. It's worked! I've had lots of applicants, some qualified and some not, but the ones I choose from mention the six weeks. It means we're on the same page for the get-go and I don't waste time with people who aren't interested.
There are plenty more suggestions and ideas for hiring someone. I'd highly recommend Chris Ducker's web site, even if you aren't hiring VAs you can apply much of his advice to the general hiring process. Good luck!