Many golfers have much tension in their arms, hands and fingers because they are trying to create club speed.  The thought for them, is that swinging hard will create more speed.  Extreme grip pressure creates tension in the arms thus inhibiting a free swing.  Less tension will create more club head speed.  Try to keep the same grip pressure throughout the swing.  The hands should be molded on the club as if you are holding a tube of toothpaste.  Only let some toothpaste out not the whole tube.  This will allow the club to square up naturally during the swing with less controlling of the club.