I have done it many times. A lot of lessons were learned. However, even now, from the heights of experience, I realize that I still can fail. The reason is that people are very creative if it comes to making impression. The more intelligent a person who sits against you in the interview, the more difficult it is to probe the true qualities of that person. Being smart is just one of qualities that you look in candidates. It defines aptitude to some degree. However, this is far not all that you may need to find out.
If a person is smart enough he or she may tell you rather what you want to hear, not what he or she is thinking. So, in result, you may get a wrong image of a candidate. Such a hire, if made, may prove to be wrong not only for you, but for a hired person as well. So, it makes sense to put it clear right before interview that this is not only the examination of person's qualities but also a test if a person fits the position. The later will be evident in a while. So, you both better not to waste time and to be honest. A candidate must be honest about achievements and experience as well as you must be honest in your responses (overtime work, salary increases, etc.). Lie leads to another lie. Don't start your relationships in the wrong way.
Now back to the interview… I used to think of candidates in terms of three A (Attitude, Aptitude, and Achievements). Fist two “A” are most important for newbie candidates. The last one is extremely important for a senior position.
Attitude is how a person sees his or her future in your company. This is a measure of desire to work in your team, the level of loyalty. And this is what candidates are dishonest about most of the time. So, do not believe just words. Look at the reaction of a person to specific questions. If there is lie you should guess it from the looks and gestures with easy.
Aptitude is how candidate's skills cover requirements of a position. Some things can be caught up at easy. Some can't. The difference is crucial. If there is anything in a candidate that makes you believe he or she will not be 100% efficient in a new role and if you are not sure you can fix that - never hire such a candidate.
Achievement is demonstration of the skills at the tasks similar to one you want a candidate to perform in the future. If the tasks are different and he or she will have to do incomparably different things then you better consider him or her to be a newbie.
Hiring newbie is more complicated because you simply do not know what to ask. Usually we ask people to describe what they did in the past and drive their talking with questions. A newbie do not have achievements to talk about, so you need to use standard cliché questions like "why you have chosen this domain?", "what have you read on this?", "what do you want to achieve in 5 years from now?", "what are you ambitions?" and so on. But those questions will reveal just a bit of a candidate. To learn more, I used to give them short tests, which allow me judge upon professional qualities. I use these tests for more than 10 years and have never regret about it.
What a test may be? Well, for a software tester this is a quick test to produce as many as possible tests for a simple function of a well known and broadly used software product. Calculator or Notepad will do just perfect. The answer not only indicates candidate’s natural ability to create test cases, it also provides you some feedback on how good a person is at using the software at all. You may guess it by the depth of the testing a candidate is generating. One may come up with tests for Undo operation, another may have it omitted.
Such tests can be developed for any position. For a developer it can be a test task to design a simple system using OOP, or to write a piece of code on a paper. For a technical writer it may be a quick description of some software function. System architect shall be able to come up with a solution to the architectural problem that you faced in the past. Or it may be just a sketchy design of a system described right at the meeting (chat machine of online magazine, for example).
Yes, such tests will require your time and time of a candidate. But you will hardly be able to gauge person’s abilities without it. Only practical task show how good candidate is at work that you want him or her to do in the future.
Of course, aside of above, there are still a lot of things to look at. How a person will be able to meet deadlines? Is the level of responsibility is high enough? Can this person learn new things quickly? Is there any problem with communication? And so on.
Sorry for this a bit clumsy but hopefully useful piece of information. I will get to it back when I have time to polish it.