What can i do to stop my 9 month old from pinching?

Gentle firm training: Patient, gentle, consistent behavior modification might work. It won't be easy. It might not work. It must be consistent. Each time it must be stopped & a firm but gentle "no" said. No gratification can follow for a few minutes. No smile, talk, eye contact. Then, all goes back to normal. Next time - the same. It works with puppies, but it's a hard job. Whatever, don't reward it w/ attention!