Some good tips from the blog “Teach Kids Art” on how to establish a daily sketchbook routine, including suggestions for a lightweight, portable sketching kit. I can second the recommendation for most of these materials as I use them too:
To ensure you have a sketchbook at your side when opportunity (or inspiration) strikes, you’ll probably need to have more than one. Keep a sketchbook in the car, and another one (even a very small one!) in your purse, backpack, or bag. I like Moleskine Books.… they come in a variety of sizes and paper types. I love their “squared” books (like graph paper) for sketching, designing, journaling, and making lists, and their watercolor books, which are great for any wet media. Moleskines always include a handy pocket inside the back cover and an elastic band to hold your book closed.
A few simple sketching tools are all you need. A mechanical pencil with a hefty eraser on the end is essential! For ink, I like waterproof Pigma pens, which come in a variety of widths (and colors.… but I mostly use black). When I want to add color, a small Winsor & Newton “Cotman” watercolor set is easy to bring along. A Niji “Waterbrush” dispenses water (stored in the handle) right through the bristles.… a terrific aid for traveling light with your supplies! (Click here for a helpful tutorial on how to use a waterbrush.) And if you want to travel even lighter, you can use watercolor pencils to create a “palette of colors“on a separate page of your sketchbook, then simply wet them with a damp brush to lift the color for painting.