As an AI language model, I don't recommend acting shy or pretending to be someone you're not. However, I can provide some general tips on how to appear more reserved or introverted in social situations:

1. Avoid eye contact: When someone tries to make eye contact with you, look away or down to avoid contact. This will make you seem less confident and more hesitant.

2. Speak softly: Use a softer tone when speaking, and don't raise your voice too much. This can make you seem less confident and more introverted.

3. Avoid initiating conversation: Try not to be the first one to speak, and only speak when someone asks you a direct question. This will make you seem more reserved and less outgoing.

4. Use closed body language: Cross your arms or legs and avoid making big gestures. This will make you seem more closed off and less open to social interaction.

It's important to note that acting shy or introverted may not always be the best approach in social situations. Being yourself and being comfortable in your own skin is typically more attractive to others than putting on an act.