[carelesschucca]

This might sound daft but when you hold the bars you should be able to ride almost without gripping, and control the bike just using the palms of your hands and your thumbs (don't completely let go) this should make your shoulders and arms more relaxed.

What it will also do is make you actually think about counterstearing as you'll end up pushing the bars with your palms instead of pulling them with your fingers... the bike will drop into corners quicker and you'll actually have better feeling through the bars. First time I was shown how to do it properly it was a revelation...

I also remember being told the Chicken thing through my intercom while I was getting my lessons, and it works... You should always be able to flap like a bird...