I have a standing desk at work, and thought that converting to a standing desk at home would help me save space. It would also let me move my home office into the walk-in closet of what would soon be a nursery. It was the first lesson in something I've come to understand very well since: baby trumps everything.
My previous desk was cobbled together out of IKEA parts, which included adjustable legs so I was able to try the new height for a few weeks before really committing. The biggest space saver was the fact I no longer needed my comfortable (but large) office chair. I ditched the large table top, cut a nice peice of birch plywood to size and topped it with a cutting mat. I was able to add a keyboard tray with a few 3D printed parts, after I modified the model to fit the wood I had on hand. There was just enough room underdeath to add a mount for my PC tower, which gives me more space to tinker on top.
Final result before I reinstalled my monitors:
Printing one of the keyboard tray parts:
The fact that everything fit was 100% luck, I didn't think to measure anything before this point:
The last piece of the puzzle will be an anit-fatigue mat, though I need to read up a bit on how well those work on a carpeted surface.
Eventually I'd like to mount the Cintiq and monitor on arms to the back of the desk or the wall behind so I can really push them out of the way when I need to. When you're workspace is only 24x36", every little bit counts.