This isn't deadly but it's easy and fun.
all you need is:
and some free time
please do not am at eyes or other vulnerable parts
Step 1: getting the card ready
take the card and put it in between your index and middle finger
on the top left corner, as you see in the picture
but if you follow step 2 and you can't do it just try it this way,
instead of putting the card in between your middle and index finger on the top left corner put them on the whole top like the next picture.