I got some good passive advice on this one. Basically, extend Uke so he is almost on his toes using good principles of ushiro tekubitori. Then either exchange legs toward the side a bit (from static and Uke has no momentum), or step forward and off to the side (Uke has momentum). Extension, extension, extension. Then drop down very low and even touch the ground with both pinky fingers if you feel a good blend and connection with Uke.

Actually, if Uke grips tight (yes, please), then when Tori rotates his wrists like Saito, Kawahara, Endo and other shihans do, Tori‘s palms will be facing out. On the aiki-otoshi part Tori can even slap his palms and/or his forearms to the ground for a great effect.