so the way you measure for a self bow- or rather the way i measure is - the central axis of your "middle finger"- is the center of the bow- so 1.25 " above that is your arrow shelf. and 3,25" below that is the rest of your handle- and where it would transition to the fade. and if you want to make the riser symmetrical- then 3.25" above the center for the top fade transition, so in effect you have 2" for a sight window.
if your hands are bigger- adjust the measurements accordingly- i know yer got big mitts ya gorilla- you might need a 24" riser :D
thats just for how i do my self bows- except i dont make the riser symmetrical- and have a longer top limb than the bottom
cheers mate-