It has taken me YEARS to figure out how to introduce watercolor thoroughly without creating total burnout. For each set of techniques students create an accordion fold book showcasing what they learned. The subject is totally up to them and the end result is extremely fun and beautiful work.
Wet into Wet on damp paper, paper dam, salt, and bruising are the first set of watercolor techniques I introduce to my students. Once they have mastered the techniques they create a miniature accordion fold book using a split complementary color scheme. They also use a planning sheet to sketch and plan their composition.
When I grade this project I use a simple checklist rubric. I personally talk to each student and use the checklist as we discuss their project. I use this opportunity to give one-on-one demonstrations if needed. I also give students a chance to make up a missed technique on the following book.
Gradient, glazing, plastic wrap, wet-into-wet on dry paper, and flat wash are the second set of watercolor techniques I introduce. They have the choice of using one of the complimentary sets for their color scheme.
During the third set of watercolor techniques I introduce control bleed, masking, rubbing alcohol, hard edge bleed, and iridescent medium. For this book they have the choice of using an analogous, triad, or monochromatic color scheme. The end product for the third book is phenomenal because they have confidence in the medium and totally get the planning process.