There are many ways hot to get playing card signed by spectator to your wallet.
Lines and video below describes one of the easiest methods I know.
There are also many ways how to control a card or how to do double lift. In my tutorial I rely that you probably already know this quite basic moves so I don't go deep in instructions in my video.
If you will struggle with this two moves, search YouTube for their tutorial :)
Now, lets get right to signed card to wallet routine! ;)