Using:
Q for military buildings
W for Eco buildings

QWERT
ASDFG
ZXCV

Visual memory is so much easier to use than muscle memory. I'm using that for my advantage for using hotkeys which are arranged in a similar way than I can see things at my screen.

Example: You want to build a house? Easy, just press Q & Q, Barracks? Q & B, etc. Castle, Q & C etc.

Same idea than here:
[You must login to view link]