Hand anatomy for reference: http://www.assh.org/Public/HandAnatomy/Pages/default.aspx
1) Is there supposed to be play in the grip, or is the club supposed to be immovable in the grip? (Please verify by checking your grip throughout the swing, slowly if it helps.)
2)What's the correct left thumb contact with the grip?
A) Entire left thumb lays on the grip.
B) Only the thenar eminence and distal phalanx make contact with the grip (with the metacarpophalangeal joint flexed and interphalangeal joint extended).
C) Only the thumb's distal phalanx should be touching the grip.
3) If you remove the glove, is your grip still secure throughout the swing or does the club shift around?
4) Do different fingers and areas of the palm apply different pressure at different points in the swing? If so, how and where?
5) Do any fingers change position during the swing, and is this normal or proper? (In my case, my left thumb's metacarpophalangeal joint has a tendency to hyperextend towards the top of the backswing unless I make a conscious effort to flex it in order to support the club. Also, my left hand middle, ring and pinky fingers tend to loosen a bit in response to gravity and the club's momentum at the top of the backswing.)