In the first year of learning OpenStreetMap users are keeping Map Features and other similar pages open at all times. Searching for appropriate tags is not easy, and if a user does not have a reliable internet connection (e.g. in Africa), they might invent their own tags, instead of waiting for a 4-megabyte page to load.
The solution is simple: print it out! Actually, no, disregard that. Let’s make a number of A5-sized laminated cheat sheets: one (probably two-sided) for most popular tags, that would be of no use to experienced mappers, and couple of specific ones: for example, for armchair mapping or downtown map features.