Just like your fingers develop "muscle memory" and know where to go, your foot and leg will develop this too. Practice! That's the only tip I know on this.
For playing pedals, you want leather soles with a high heel. For male players: one option is (expensive) cowboy boots. Classical organists and pro jazz players have their shoes custom made. If you are going to play "fast" these are necessary.
(I practice quite a bit with my eyes closed. Does anyone else do this?)
The jazz players, who play left-hand bass, don't switch the Leslie much.
(My humble opinion - your's may vary and I may be wrong: The Hammond organ is a sythesizer. Synths are bascially played with the right hand while the left hand controls the instrument. So, in this case, it's left foot and right hand, where the left hand and right foot are controlling the machine.)
Years ago (sorry about the geezerama), when I was playing pedals, organ and electric piano (in a rock and roll trio), I didn't have a free hand to swtich the Leslie. So I built a switch that attached to the side of the expression pedal. (Tony Monaco uses one of these on his Hammond.) One of the top Hammond techs in the country builds and markets this type of switch as the "Sidekick". If anyone is interested, private message me and I will describe the device and send you the link where you can order one.