What can help on a searching side too is to shorthand searches, such as:
resi = residential,
amb = ambience,
backg = backgrounds,
met = metal,
plast = plastic,
It may seem like it only shaves a fraction of a second off a search, but added up over time, it saves a lot of time. As mentioned, Soundminer is a top choice. With it you can do boolean searches which are quite amazing. In many cases, I've used them to effectively get a handful of results on a search to find what I need instead of thousands of files that I don't need.
An example would be:
amb cit traf day -bird -siren
This would mean that it searches for city traffic ambiences that are daytime, but without birds (if the file was tagged properly), and without any sirens (of tagged properly)
This function proves to be very powerful
One note: Soundminer and other search tools are not 'contextually intelligent'. This means that if a file is tagged with the text no birds, and you run a search for files that are -bird, it will NOT show that file because the word bird was tagged it, regardless of having no in front of it. Lesson? Only tag what the file has, not what it does not have (except under specific circumstances)
I know this answer is somewhat of a tangent from the actual question, but it does relate to it in the sense of effective search ability and time saving.