It also depends is your're left or right handed...
But in general i would use a big playeble filter knob at the top so you can rest your hand on the top, for extra precision. I like to have sequencer or playpads or joystick like modules on the bottem (if the bottem row is horizontal)
Basicly the " set and forget" modules in the middle and the more playable ones on the edges. so that the spagetti is not too much in the way.