This lightweight homemade set of 20 watercolours and kit in one tin means there is no excuse to do nothing.
A layer of thick plastic (melinex) separates paint from brushes and acts as palette. I can fit in 11 items (a wetting out brush, 3 sables, 2 reversible brushes, an HB pencil, rubber, sharpener, and 2 grades of black watercolour pencil). No room for water, which I carry in a miniature drinks bottle plus a soya sauce bottle for individual drops.
At the moment I'm trying out a Royal Watercolour Society Fabriano Artistico sketchbook. A plastic sheet keeps the paper below dry when painting. I've just sawn up my watercolour pencils so I can take a mini set to France. I tested them out on this View of Glastonbury Tor from Draycott Slates last week but they don't work as well as I hoped on this paper. Despite being hot pressed paper it still has more texture than the Sennelier Grande Luxe sketch book I normally like to use.