Lack of drawers.

The desk where I spend several hours per day is the Ikea Table Norråker. It has a little flaw: it has no drawers. Luckily there about 12 cm from the apron (the wooden panel that connects the legs and the top) to the edge of the surface, so I designed several drawers to put in that space.
You can find the 3d printable models and a more detailed description on Thingiverse.