A bit of misdirection goes a long way in this illusion. Where did the ring disappear to?
Your ring disappears, only to pop back into place instantaneously. Or does it?
The ring will impossibly switch fingers right in front of your audience. One moment it's on your ring finger, the next it's on your ring finger. A little tug and pull is all it takes for your ring to penetrate your finger and change positions in order to impress your audience.
All you need for this crafty trick is two identical rings and a little time for practice. By the end, it'll appear as though one of your fingers dove inside the ring, keeping it from falling to the ground somehow.