Does this sign mean 'single' as in 'only one item' or 'unmarried'?
This specific sign on the chin is most commonly used to mean 'single' in the context of relationship status, meaning unmarried or not dating. If you mean 'single' as in 'only one item,' you would typically just sign the number '1'.
Which side of my chin should I tap first?
If you are right-handed, it is most natural to tap the right side of your chin first and then move across to the left. Left-handed signers will typically tap the left side first and move to the right.
Should I drag my finger across my chin?
No, you should avoid dragging your finger across your skin. The correct movement consists of a light tap on one side of the chin, lifting the finger slightly, and then tapping the other side.