I picked this up from my son's awesome piano teacher - when he is doing something that is uncontrolled or overexcited, I say in a loud voice "Thank you for not throwing your clothes" or something appropriate to the occasion - e.g. "Thank you for not blurting out the answer and waiting for your turn". This seems to have a great effect on my son and reminds him to behave and he immediately stops the undesired behavior. I agree with syoblrig that gifted kids should not be let off the hook because they might possess overexcitabilities. They are eventually going to merge with normal people in society, join a workplace etc and will not get any free passes for behavior because they have overexcitabilities. Just remind him constantly that it is not easy to live around a kid who does these things.
For the throwing clothes thing: DH decided to let it go, but, I could not - so we compromised and set up a basketball hoop on top of his hamper and he throws his clothes into the hamper through the hoop
