Sitting will kill you. It's almost as bad as smoking. Don't believe me? Read Arsebestos, by Neal Stephenson in his compilation Some Remarks, or more fully, Deskbound by Dr Kelly Starrett.
So as a matter of urgency, I created a standing desk adaptation for my work space at the Waterfront Studios.
The heart of the desk is a lovely piece of walnut, left over from both my sister's bookstand, and Heli's meditation stool. The design is just two boxes, one tall for the monitor, and one wide for the desk surface:
The boxes are dovetailed together out of broad pine planks which I machine cut to length at the awesome Ipswich Makerspace. At home, I added a solid wood banding on the fronts. Oak for the monitor box, and maple for the desk. I did drop the desk box at one point, amid much swearing, and had to patch the corner:
Top tip for cutting dovetails, or any joint: make every cut truly vertical. A pocket level helps. As I'm cutting pins at right angles, in this case the top surface is level. Cutting tails, I'd put the piece in the vice at an angle and use a set-square on the (level) bench to check. This way your natural sense of plumb won't drag the cut out of line.
The critical thing is the heights; they must be absolutely perfect for the ergonomic advantage to work, so both boxes have cork feet. Sorry about the shitty gappy joints. No excuses.
I finished it the whole thing using only hand tools, and no sandpaper; I went all James Krenov on it, and the finish is straight from the plane, with just a whisk of French Polish to bring out the colour.
I did cheat though and use a router to cut a very deep groove in the top to fit the battery compartment on my Apple keyboard and trackpad. It puts them at a much better angle for my wrists.
Note the level; got to check that gravity is working for you, not against you!
This all took about 30 hours of my free time, so it's definitely not a commercial solution, but I don't care. I spend a lot of time at my desk (sometimes as much as four whole hours in a day!) so it's worth getting it nice.