I paint using a small Schmincke metal travel palette. I ordered the blank palette then filled it with Winsor and Newton half pan watercolors. I chose this particular palette because it is small and has several areas for mixing colors. I found that over the years the plastic palettes yellow and turn brittle. The colors from left to right starting with the top row. Turquoise, Ultra Marine Blue, Paynes Grey, Terre Verte, Sap Green, Cadmium Red Deep, Alizarin Crimson, Cerulean Blue, Naples Yellow, Cadmium Yellow, Naples Deep, Quinacridone Gold, Burnt Siena, and Raw Umber.
Since I recently revised the colors, I decided to make color charts on 4 1/2" X 5 1/2" paper. I use fourteen colors so there are fourteen charts, one for each color. (Example: I take one color, then mix it with the other 13 colors, one at a time, to see the variety of colors possible. This is a great way to learn about color!) The blue brush in the photo is a large size Pentel water brush. Large refers to the size of the brush tip. It is filled with distilled water. This eliminates having to carry a water jar.
Other items I carry in my portable art pouch are: a 6", 45 degree transparent triangle for drawing lines or boxes; two mechanical pencils - one with .7 leads for the initial drawing, and another .5 mechanical pencil but I replaced those leads with 2B leads for the final drawing and for great dark lines; #3 X-acto clips also known as bull clips to hold pages flat; a retractable white eraser (Staedtler or other brand); a Sanford Design Ebony Jet Black Extra Smooth pencil (makes great thick, expressive dark lines); and paper towels.
Some of the charts I've already painted.
Testing layouts and colors for a street scene. This is probably the third and fourth version of this painting! These study drawings are small, 3"x4" each. When I paint on large pads/notebooks, I use different brushes: a set of Escoda brushes which hold a lot paint and are round; or a different set of brushes to fill in large areas especially for buildings: a flat 3/4" brush, a number 10 round, and 1/2" and 3/4" angled brushes.