i’m using tags instead of subcategories for most things. a problem with this is you have basically no control over how this is presented to users in the navigational sense. you can’t order, emphasize, or de-emphasize tags, and they don’t really appear on /categories like subcategories do.
best solution i have so far is to create a site map topic and link to it wherever it makes sense. that could include in the sidebar (atop Categories section or somewhere in the Community section).