Holding the pick and tension

Yes.  I think that not enough emphasis is given to holding the pick when you see 'how to learn' books and videos on the guitar.

I've also found that using a really thick pick has improved my playing a lot, and helped to reduce tension in my shoulder, of all places.

I use the really thick v-picks now because I get less muscle fatigue in my hand.  Some people say these picks have a lot of 'string chirp' which is true, but once again, changing my picking style to try and reduce the chirp means that I am now hitting the strings at more of a 90 degree angle which has improved my picking accuracy and cleanliness too.

As with most complex skills using hands - it is important to stretch/warm up on a regular basis.

And like any exercise, it is also important not to overdo it.  Remember, if it starts to hurt, then STOP!  Same thing if you have ongoing pain in the wrist or finger joints - take a break and if the pain persists, see a professional physio/doctor.

I took a 15 year break from playing guitar, then took it up with earnestness and was playing for about 2 hours a day.  I soon got really bad pains in the top 2 joints of my left hand fingers.  I actually thought I was getting arthritis.  My technique also started to slip a bit, and I was devastated.

It was only when I went away on a business trip for 7 days and didn't touch guitar for all that time that the pain went away and I was able to enjoy playing again.

I've since learnt from that never to overdo it again.  Also, changing my practice routine so that I was focusing on different things helped.  For instance, I don't just mindlessly do repeating scales faster and faster all the time like I used to.  I now try and work on specific licks and getting some 'feeling' in my playing.  I also make sure my fingers are already warmed up and flexible before trying and bends or vibrato.

I now practice for around 60 to 90 minutes per day.  Sometimes I find that if I take a whole day or two break in my routine, my playing is actually BETTER when I go back to it (once I've warmed up of course).  This fits the concept of most exercising and body building etc. - It is good to work out regularly, but sometimes your body just needs a short break to repair and heal itself.

Best of luck!

Picking is a very fine art form.  I have always been a traditional 'alternate picker' and I remember when I tried to learn sweep picking, it absolutely killed my technique and normal picking style.  I had to give up on sweep picking.

I guess it comes down to 'muscle memory' and how your brain gets attuned to a particular picking style.

Do you find that the problem becomes obvious after you have concentrated on just one particular picking style?

I know when I was younger (as you are) it was easier to chop and change picking styles, but now that I am older, my brain is set in it's ways I think, and any NEW picking technique I try tends to mean I get worse at other techniques.

For instance, I try and use just fingers every now and then, and find when I transitions from several days of using a plectrum to using fingers, there is a period of 'stiffness' and re-learning required.  Same if I go back the other way.

Just to be on the safe side though, I'd strongly suggest you talk to a physiotherapist about this issue.  He/She might be able to detect if it was some sort of early stage carpal tunnel syndrome or repetitive stress syndrome.  If that is the case, you REALLY want to catch it early and treat it before any permanent damage can happen...  At the very least, they may be able to show you a routine of stretching exercises that may alleviate the stiffness.

Better suited to the Gear section, I think. It'll certainly attract more attention from players there.

Right hand technique is something I've been working on, watching video's about and reading up on... and i must admit that the more poke around the more confused i get but i can say there are a few consistencies in what folks are saying. Some has already been stated or eluded to in this thread.

One is that being overly tense is a big negative. Just like any component of playing, if you are straining you'll tire out and struggle, relaxed but controlled seems to be the idea.

The other thing I've come across is the notion that picking quickly with good articulation is a very specific type of picking and should be treated as such, you should in essence change gears when doing different types of picking, the trick is the transition, balancing the dynamics and making it natural

The thing I'm finding is picking is kind of like working on your golf swing, there are all sorts of concepts and gizmos out there, tough to know what will work for you and what will actually get you to where you want to be... I think i am personally going to have my guitar teacher have a look at what I'm doing, give me some pointers on technique (like angle of pick relative to the string, grip and so on), and try to give me a couple of practical approaches for my level of playing to getting things better.