Elbriga (of Calvin and Hobbes fame) is also an active voxel artist. He's running a weekly voxel challenge on Twitter and Facebook and the entries are typically good fun. Care to join?
If you're looking for a fun and quick weekly challenge similar to Pixel Dailies, but in 3D, you should consider entering our WeeklyVoxels challenge!
Each week a theme is given and you can submit your entries by uploading to Sketchfab and sharing it on the Twitter page or Facebook group. You can read more about the rules there.
This week theme is #FOOD! Don't hesitate to jump in! The goal is to have a cool community that gathers around fun 3D creations every week, and everyone is welcome.
MagicaVoxel [open source too! - Bart] is a great starting tool, and you can polish your creations in Blender as well.