For the shadows i wear often, I have a 15 pan palette with cool colors, and a 15 pan with warm colors. That way, i can just grab one depending on my outfit. In each 15 pan, the shadows are organized by ROYGBIV.
The colors I always wear (basic wash, highlighter, brow, liner) are together in one 4 pan.
The colors i dont wear often are grouped in 4 pans based on color (greens in one, purples in another, etc). Any shadows in pots are lined up on the second tier of my traincase, so i dont have to dig for them.