talkmagic.co.uk

Do you do the snap change often?
How do you do to "cover it up" when its done?
How do you do to not show them the "hidden card"?

Personally, I think you can only do the snap change for one person. Or, if you are making a video-tape. However, to end up 'clean' at the end...once the change is done.. turn your hand palm down, lap the card then push it forward on the table to your spectator. Remember watch your angles!

I try to practice it every time I get my cards out.
Unfortunately I'm still no good at it

But I'm getting there.
I cant really think of anyways of ending clean. I guess there's always the "put the cards back on the deck and push off the real card" move, but in my eyes, putting a card back on the deck during performance comes across as suspicious.

I like the idea of palming though.
Turn your hands palm down, palm the top one, and move the bottom one away from you. Smooth and natural

If you can do it quickly and squarely you can drag the revealed card back to where the original card is. Doing this quickly and leaving them square will make this near invisible and leave you with another double. It's damn difficult to leave them exactly square though.

Also, if you're doing this to finish off a card routine and are leaving this newly revealed card on the table you can drop the unwanted card on top of the deck as you lean down towards the table to drop the revealed card. This is a nice alternative to lapping if you aren't seated and you also don't end up with a card in your damn lap!

Jeff McBride teaches a clean method on his art of card manipulation series (can't remember which one of the three).
Hold the deck of cards in your other hand (if you snap with your left hand, then hold the deck in your right hand). Then when you change the card, the hand with the deck will be very close to the hand that changed the card. Now you can drop the hidden card back on the deck and you are totally clean.

I used the method taught by Oz. I think it's great and there's no need for palming or anything. Here's a quick video showing the change.