Thought this might be useful to some people..
I decided to make a mahl stick to help out when I do larger paintings. However I saw some things that I didn't like when I looked at sticks to buy (including the cost!). So I thought about it a bit and then made this mahl stick which was very inexpensive to build.
Here is the stick propped up in our kitchen:
First of all, notice that is not a round pole. A round pole puts more pressure on the palm of your hand as the surface area is quite small. The best shape would be a flatter surface with no sharp corners. I found a piece of pine 'quadrant moulding' style wood for using on skirting boards:https://www.diy.com/departments/quadrant-moulding-t-16mm-w-16mm-l-900mm/1240037_BQ.prd
This has a nice curved shape with no sharp corners:
I also decided that a hook on the end which I could put over the top of my easel / panel would work better for me than the cloth ball often used at the end. So I found some hooks with a screw on the end which you can screw into the soft pine without even using any tools. With the help of some pliers I expanded the hook angle a bit and it works very well:https://www.diy.com/departments/b-q-zinc-effect-metal-cup-hook-pack-of-10/203622_BQ.prd
I only needed 1 hook, but they didn't come in less than packs of 10.
Still.. total price for wood and hooks, and with 2 minutes of screwing in the hook by hand was £3.39
Hope it gives people some ideas!