There are two questions that other recruiters seem to ask me the most frequently, and those are - "How do you find such great candidates?" and "How should I properly use boolean search strings?". To answer the former, I would say, "Hard work, diligent prospecting, and a thorough understanding of my requirements!". For the latter, I would answer, "Well, that depends on what I am doing in my search."
I think boolean search strings can be a great tool for sourcing candidates, but only if and when they are used appropriately. It is all too-often leaned upon by professional recruiters as the end-all be-all of all sourcing efforts, and substituted instead of good old-fashioned elbow grease. When I tend to think it works well is when using it for setting up automated search strings where the results come to you once a day, and on a specific position; in this scenario, it is ideal. The results are sorted through by machine, providing a quick run-down and a neat data-set for review. The problem arises when a recruiter makes the critical mistake of believeing their sourcing labor ends with those results. If a recruiter is relying too heavily on the yield of developed search strings, they are not doing their client or their business any favors.
In addition to running these developed search strings, I prefer to run a series of manual some-what generic search strings against my requirements throughout the day. The reasoning behind this is because we know boolean does produce specific results, and we also know that by that same nature, they can be very limiting. I almost always find that running the generic search strings in addition will yield more resumes to review for every client. They may not all be specific to the position, but there are many times they are applicable to other requirements I have available, and the extra effort I make in prospecting and research will pay dividends down the road.
"But there are so many resumes that come up when I run a general search, how can I possibly get through them all?"
The point here is not to get through them all, to reach a point of completion, but to hone your reading and assessment skills. The more intricately you know your open positions and what they require, the more you understand what the hiring company's values are, the better your ability to match them with candidates. Spend time understanding the needs of your managers, teams and clients ... make yourself an expert on the company culture, expectations and preferences. Learn to read through a resume the way your hiring manager would read it. Look for the things they look for when reviewing. "Would this person make a good team fit?" "Would they excel in the position, given the environment?". As you become more effective at this task, your ability to assess a resume for a potential match will quickly increase in both speed and accuracy.
Take time to make the boolean search strings. Leverage them as you need to do so. But don't forget you are the front line of HR, your ability and experience is leaned on heavily to provide relevant and accurate results in a limited amount of time. Boolean search strings can help to find the best possible candidates, but finding all the possible candidates still is a feat accomplished through strategy, diligence and a lot of reading.