Here's how to fingerspell "g":
1. Start with your dominant hand in a "5" handshape (all fingers extended).
2. Bring your thumb across your palm and touch the tip of your index finger. This creates a "g" shape.
3. Hold this shape and position it in front of you, at chest level.
You can use this fingerspelling to sign "g" when it's used as a letter, like in the alphabet. If you are signing a word that starts with "g" like "good", you would sign the whole word using a single sign.