I am always looking for new exercises to stretch and make gigging less of a physical chore. If you have ever played a whole week of four-sets-gigs with a heavy Les Paul on you shoulder, you know you will feel better if you stretch before and after your gig, even just for a few minutes.
I bumped into this set of stretches for your shoulders and I must say I found them to be great. Practice them slowly at first! Know your limits!
This is the link:
http://www.mindbodygreen.com/1-7459-1/8-yoga-poses-to-help-cervical-spine-neck-issues.html
This is another great stretch/warm up for your finger to do before and after your gigs and long practice sessions. Remember to warm up your hands (or any part of your body) before stretching and get your blood flowing. Never stretch from ‘cold’.