When I am teaching students how to search more effectively, we begin with the "Ladder of Abstraction" activity. The goal of this activity is to move thoughts from abstract language (non-tangible/general/vague) to concrete language (tangible/specific/meaningful).
Here's an example:
The starting word is TRANSPORTATION. Transportation is an abstract term with many different meanings. We can start to narrow it down in steps. The materials in this day 6 lesson refer to this process as "stringing it out".
Transportation -->Vehicle -->Family Vehicle --> Mini-van -->Dodge Grand Caravan
Instead of having a vague idea of something that has to do with "transportation", we have a concrete idea that we can relate to. We could get even more specific with year, package, colour, etc.
Take away: If we ask research questions that include concrete language, we automatically have some keywords to use in our search, and therefore, we will find more relevant information easily in a shorter amount of time.