Nebo knows some.....I probably should have looked somewhere for the best signals to use.......I just made them up, they just kind of happened that way. He listens to hand signals as well as verbal for the most part, he is especially good at "sit."

Sit--index finger pointing up
Down--index finger pointing down (sometimes have to lower arm also)
Stay--hand up, palm facing him
Shake--snap fingers
Speak--some strange hand movement I can't explain lol
Up--arms crossed on chest
Come--hand patting leg

there's probably more but that's all I can think of