LYRA Osiris Water-Soluble Colored Pencils, 3mm Cores, Set of 12, Assorted Colors (2531120) Water-Soluble pencils a great way to introduce watercolor painting without the mess. They are great for sketching on the go using a water-brush.
Crayola Erasable Colored Pencils, 24 Non-Toxic, Pre-Sharpened, Fully Erasable Pencils Colored Pencil Set for Adult Coloring Books or Kids 4 & Up, Great for Shading, Gradation, Line Art & More Water-brushes are great with water-soluble pencils, and watercolor pans. They allow for on the go painting with little mess. This Niji works really well.
Letraset Pro Marker, Twin-Tip, Hues, 5-Pack This brand i like, and the various sizes are good for backgrounds, filing in, and fine details.
Crayola Giant Marker and Watercolor Pad Most colored Pencils are not erasable, which makes these great for sketching and coloring.
Darice 4-Piece Pencil and Pastel Blending Set Pro Markers don't create lines between strokes.
48 Soft Drawing Chalk Pastels in Brilliant Assorted Colors Water Color Paper absorbs more color and water runs less. Markers are smoother.