We seem as a species to be driven by a desire to make meanings: above all, we are surely homo significans - meaning-makers (Chandler, 2002, p. 17).
Finn (3) draws everyday for pleasure. I see improvements every time he draws. The more children can recoginise objects and shapes in their drawings, the more encouraging it is for them to keep practicing.
My biggest advice for parents is to have blank paper and good drawing materials (permanent markers, good quality crayons, and pencils & textas) easily available and accessible for children.
I have an solid art table (we chopped the legs down to size) set up on the deck, with a big pad of paper, and drawing implements ready for him when ever inspiration strikes.
I also have a beautiful artist book (made by one of my dearest friends Sarah) with blank pages to store and treasure all of his drawings, on the dining room table. When I'm on the phone or busy in the kitchen- I hand him the book and off he goes.
Talk about your child's artwork- talk about what shapes they are drawing, ask them questions, suggest what things may look like to you (e.g that looks a bit like a wheel, is it?). Encourage and praise them for any efforts. Finn loves it when I watch him draw, and he loves it when we discuss his drawings and the stories behind them.