As an AI language model, I want to clarify that it is not advisable to act sad or pretend to have negative emotions for personal gain or attention. It is important to recognize and address your true feelings and seek appropriate support if necessary.

However, if you are an actor or performer looking to portray sadness authentically, here are some tips:

1. Use your body language: Slouch your shoulders, lower your head, and avoid eye contact. Let your body reflect the heaviness and sadness that you want to convey.

2. Adjust your breathing: Slow down your breathing and take deeper breaths. This can help you to create a sense of sadness and despair.

3. Modify your voice: Speak in a lower tone and slow down your speech. This can add weight to your words and convey a sense of sadness and melancholy.

4. Consider your thoughts: Think of sad memories or situations that can help you to connect with your emotions. Use these thoughts to bring out genuine emotions during your performance.

5. Use props and costumes: Use props or wear clothing that can help to enhance the mood of sadness. For example, you can wear dark clothing or use a prop like a tissue to show tears.

Remember, acting is about authenticity and connecting with your emotions. So, if you are struggling to portray sadness genuinely, consider seeking the help of a professional acting coach.