I add things to my own local area .. and to areas that I'm thinking of visiting.
Adding New Tags
Adding tags appears to be difficult in the 'approved' way. Yet tags are added .. unapproved, not voted on. So why bother with the approval process? Simple... so that others can have an input .. and possibly come up with better ideas.
Some argue that new proposed tags don't follow a present tag or a present tag system .. yet these present tags don't follow other tags.. There needs to be a 'plan' on how tags are organized, the philosophy of tags if you will.
My present thinking is tags should be;
A) What is seen on the ground. A bad example is amenity=drinking water. Is this a tap, a fountain, a river, a pond, a water tank?
B) Organized into functional groups, preference given to transportation? Bad example? amenity=fuel .. this should be either highway=fuel or waterway=fuel.