Article: Sit at a table with your elbows on the table.  Be sure you have on a shirt that is tucked in (any sleeve length is acceptable). You may even want to ask them to provide the coin, but warn them that you’re going to make it disappear and they won’t get it back. With both elbows on the table, holding the coin in your right hand, rub it against your left forearm. Pretend to fumble and accidentally drop the coin on the table next to your arm so that you audience sees it.  Pick it up with your right hand and tell them that it works better with the other arm. Pretend to put the coin in your left hand, but really keep it concealed in your right hand. Pretending that the coin is in your hand, rub your left hand against your right forearm. Be sure that you make eye contact and chat with your audience while you are performing the trick.  That will distract them and make them more likely to miss the sleight of hand. Because both of your elbows are on the table still, your right hand (with the coin in it) should be even with the collar of your shirt.  While you are distracting your audience by talking to them and pretending to rub the coin on your arm, drop the coin in your shirt.

What is a summary?
Set up for your trick. Show a coin to your audience. Rub the coin on your arm. Drop the coin. Pretend to transfer the coin to your left hand. Rub your left hand against your right forearm. Distract your audience. Drop the coin into the collar of your shirt.