Just thought I'd share a teaching idea that wasn't mine. . .but I use it daily! I believe the Kindergarten teacher at our school went to a workshop once upon a time and got this idea from there. She used, and now I also use, these big posters in the classroom to encourage students to "excel" in their art (drawing and colouring pictures). In grade one, especially at the beginning of the year, pictures are used to tell stories, to be labelled, to add to writing that was completed. . .whatever. So, I try to teach my kids that if you are making a picture, make it "BIG!" After you have made a picture that fills the whole picture space, add details, or make it "Beautiful!" Then once the picture has all the appropriate details, make it "BOLD!" Colour it neatly and completely!
Here are the pictures/posters we use to teach this: