Keeping my current city and my home town up-to-date.
Couch mapping of the streets in some sparsely mapped, inhabited areas of the world.
Searching for yet unmapped toponyms used by locals.
Trying to add anything I know about any places I've ever been to.
Searching for obvious mistakes, misspellings, misuses and nonsenses and fixing them (sometimes in bulk; IMO such edits, done carefully and sparingly, should not be considered bad mechanical edits).
My past, larger activities:
Manually collecting address points around Trippstadt (emphasizing hamlets and isolated dwellings) and surrounding villages.