The most common fault I see in chipping is trying to chip with your hands and arms and not your body. This encourages too long a back swing for the swing distance required with short decelerated follow through to send it the correct distance. The result is very inconsistent distance control and an inconsistent strike i.e. fats and thins.
There can be a number of reasons for being too ‘handsy’ but there is a drill you can do to easily change that. Do some practice chipping with your trailing foot crossed over your front foot. This will restrict your back swing and encourage a positive full finishing position that will be based on the body not the hands and arms. Whilst doing this drill all you would have focus on is keeping the butt of the club pointing at your belly button at all times! Using this drill you will find the strike is far purer and more consistent.