Although I haven't been posting daily art since the beginning of the year, I haven't stopped making it. In fact, my 2018 project is perhaps the most complex project I've tackled in my almost two decades of daily art. Instead of specifying a format (such as the 3x5 or 4x6 index cards I've used several times) I've specified a theme: maps. Each day I am making something having to do with a map, but anything goes.
Sometimes I make a piece of art incorporating a map. Sometimes I draw a map in a sketchbook; it might be a copy of an antique map, a map of a real place, or a map of an imaginary place. Sometimes I cut something from the newspaper and annotate it with a map.