Here are some tips for the classic palm that have worked for me and which you might find useful. This will assume you are right handed:
Holding the deck face-down in your left hand in mechanics grip/dealing position, push the card forward with the fingertips so that it is outjogged about half an inch. Then, while addressing a comment or a question to a person or to the audience, and looking at them (not your hands), push downwards on the outer end of the out jogged card with the fingertips of the right hand. This will provide a lever, and the card will pop upward into your right hand. Use the left fingertips, which are underneath the card, to help push it into the right hand, to secure it, and to adjust the angle at which it goes into and sits in your right hand. The right fingers are completely closed both during this process and after the card is secured in your hand (no "windows").
Experiment with this in front of a mirror and you will eventually be able to make it smooth and undetectable. Do not do it when anyone is looking at your hands. And do not look at your hands as you are doing it. Once you have the card secured in the classic palm, grip the deck from above with the right hand thumb and fingertips, letting the left hand fall to your side (or onto the table if you are sitting down). Be careful that your right hand hand is tilted downward and a little bit inward toward yourself so as not to expose any of the angles and flash the card (especially if you are standing and they are setting).
Holding the deck with the hand that is classic-palming the card gives the hand something to do, rather than just looking awkward -- it makes the hand look natural and provides a justification for why the hand is in the partially closed, cupped position. Eventually you can transfer the deck to your left hand, and immediately after you do this transfer, drop your right hand casually to your side close to your leg with the back of the hand facing outward until it is time for you to do whatever you need to do with the palmed card (such as replacing it on the deck after they shuffle, putting it in your pocket, getting it under a drink, or whatever). After you drop your right hand that is palming the card to your side (or to the table if you are sitting down), do not place your right hand behind your leg, or your back, or act like you were trying to hide anything. Being relaxed and casual is the key, and this will come with practice.
If you wish to palm more than one card at a time, get a pinky break under the cards with the little finger of the left hand, pause and address a question or comment to somebody or to the audience, and as you do so, push the cards forward as a unit with the right thumb until they are out jogged about half an inch from the outer end of the deck (as described previously), then push down with the fingertips and all the cards will pop into your hand.
