We all know that search is completely ineffective when looking for a particular theme style. The majority of the buyers first like the theme, then make something out of it. But those buyers who already have a sketch of how they want their site to look like, have a tough time finding the themes relevant to their requirement.
I think having an universal suite of keywords will help users narrow down on their choices. WE need to have more than 20 keywords. We need to cover every design aspect of a theme and categorize them with site wide keywords. I believe we authors can best describe our works, so I request everyone to come forward with descriptive keywords for their themes.
Then we can collate these keywords in a TF dictionary and assign the keywords which describes each theme. This will lead to more buyers finding the theme that they have a sketch of, in their mind.
Please think from the shoes of a buyer who has a preset design in their head, and dig super descriptive keywords. Much more specific that what we have now.