The way AJ does it is very musically correct. I find guitar "licks" are easier for me to play in F or G than E, so I normally split the keyboard so that F or G is the lowest lead note. Then I often cheat and use the transpose button so that the keyboard sounds in E. This also allows me to play more variety of chords (some inverted) with the left hand before running out of notes on the high side.
There are many ways to do it. You must experiment and find which way suits you best.
This area is where I really prefer 76-key arrangers, but we must adjust to what we have. As they say in the South "Dance with what brung you".
I will interpret this if necessary.
DonM