Over the winter I built a small 9" x 12" pochade box from some leftover walnut and plywood. It spent about $15 on a few fittings and a small can of varnish, the rest was made from things I had laying around the house.
I constructed the bottom section of the box (i.e. the palette holder) with dovetails and inset the plywood base into a rabbet on the underside. The lid/easel has a sliding mast and has horizontal slots so that a panel can be braced to it using miniature bungees. The panel rest is adjustable.
The palette is a piece of glass taken from an old metal picture frame and cut to size.
I made the side brace adjustable so that it can be locked in a range of positions. This enables the entire pochade box to be angled and still preserve a correct working position.
The side tray is a $3 plastic kitchen tray that I found at the grocery store. I fashioned some clips from shower curtain hooks and it seems to be sturdy enough.
The pochade box can be used as a desktop sketch box or mounted on a tripod (as shown). The tripod I have is a ball head type with carbon fibre legs and center post. It will easily hold 20lbs.
Starting a painting in our back yard.