I have been putting off writing this as I hoped we would be able to sort out Po's aggression issues on our own. He's just over a year now and has been biting us since we got him. As a pup we tried everything, from the water bottle, to compressed air, 'No', 'no bite', 'uh uh', all of it. The turning our back when he bites is a complete failure as it hurts when he bites and we're unable to ignore the behavior. We're contemplating clicker training him- but will this be a good way to train him out of attacking us for no good reason? He bites mostly as a form of play, or to get our attention. It seems to happen most when he's excited. He's fine on his leash though- never aggressive when he's on that.
A foreseeable problem we have with clicker training is his persistence to get food. If we have treats on us all the time he will be up on us, trying to get them.
Note: We've tried a trainer but none of the recommendations worked- her main philosophy was ignoring the behaviour but that's hard to do when it hurts. We were told to wear more appropriate clothing (it was summer and I was in shorts) but I think its unrealistic to expect us to wear jeans, a long sleeved top and boots in our own house especially in the heat of summer.
I just want to say that despite this Po is a great dog- he's cute and can be a sweet dog. He's a little slow on the uptake when it comes to learning new things, but we love him so much despite his annoying tendencies. We really want to figure out a way to curb his biting behaviour.