I have suffered from cramps in the left wrist to the extent that sometimes I simply had to stop playing.. I have tried different postures, had doctors check it out etc etc.. just must have developed a weak wrist... but I have been playing for around 40 years and hope to carry on for another 40!! My remedy is simple and has been covered here on this thread: use a capo from fret two upwards, play in open tunings if you can (hey it's a lot easier on the wrist and often sounds nicer anyway!), make sure you have a low action on the guitar and if possible a thin neck. Songs where you strum holding down chords for long periods hurt a lot. Fingerpicking where you constantly move fingers around with the left hand going from chord to chord and often smaller versions of the chords, works well too. Another trick is to make sure you have a decent break between songs. If you perform in public make sure you do some good chatter between songs and do the odd song unaccompanied to give the hand/wrist a rest and throw in a poem or joke. Importantly take your hand off the fretboard and let it relax. Try to relax generally too while playing. Being "uptight" can bring these things on too. None of these are solutions but it does help eliminate much of the problem. Paul