Remember, the palm requires misdirection. Don't be nervous. If you're nervous, the spectator will notice. Contrary to popular belief, spectators are not circus chimps.
If you ask a spectator to shuffle (even better if they ask you) then hand, then try and bring the attention up to your face, your eyes, look at them - talk to them - tell them they can shuffle. Whilst you do this - palm the card. IT doesn't have to be invisible; In fact, a palm is rarely invisible to a looking eye. But if you keep their attention elsewhere - all shuld be well
G