Watercolor winter wonderland, 5th grade

Over the years I've done this project, I think I've finally figured out how to get students to make horizontal lines in the water.  I have them hold their brushes at a 45 degree angle and pretend it's in a vice, unable to move.  They can go side to side and up or down, but they have to move their entire arm so it reminds them to keep their lines horizontal.  The water in this year's project looked much better!