My approach 
Please note that I do not attempt to classify images to all possible categories or by adding them to pages. I however ensure that they belong to at least one suitable category and include the description which has the keywords needed for a searcher to find the image. In all likelihood the image will also be in use on a relevant page on the English wikipedia.
It is particularly unfortunate that Commons / Mediawiki lacks the semantic plugin or other such alternatives - which can lead to a potential explosion of categories. For instance there is "Category:Bird family Y" and "category:Birds of Location X" and then there are passing users who create "category:Birds of Location X belong to family Y" - this is clearly non-scaleable.
- Ibis 1920
- PZSL 1903 2