Hello,
I sent an email about this to the Wikidata mailing list already, but for those of you who run your own Wikibase instances - I'm pleased to announce the release of Forage, a new JavaScript-based editing tool that provides a more structured, and easy-to-use, interface for adding data to a Wikibase-based wiki:
https://github.com/sanjay-thiyagarajan/forage
It's only been tried on Wikidata for now (as far as I know), but in theory, getting it to run on any Wikibase installation is fairly simple, as long as that installation has properties that are equivalent to "instance of", "properties for this type" and a few others (see documentation for more details).
Forage is now part (the final part, I would say) of a suite of tools that I call "Enhanced Wikibase", which make a Wikibase installation more like a traditional database-backed website:
https://wikiworks.com/enhanced-wikibase.html
I hope people try it out on their own Wikibase wikis. I and the other Forage developers look forward to any feedback!
-Yaron