You can promote hair thickness with homemade hair masks that nourish and strengthen your strands. Here are some recipes:

1. Egg and Olive Oil Mask: Beat 1-2 eggs and mix with 1 tablespoon of olive oil. Apply to damp hair, focusing on the roots and ends. Leave for 30 minutes, then rinse with cool water and shampoo.
2. Avocado and Banana Mask: Mash 1 ripe avocado and 1 ripe banana together until smooth. Apply to damp hair, leave for 30-60 minutes, then rinse with lukewarm water and shampoo.
3. Coconut Milk and Honey Mask: Mix equal parts of coconut milk and honey. Apply to damp hair, cover with a shower cap, and leave for 30 minutes to an hour before rinsing with cool water.
4. Aloe Vera and Castor Oil Mask: Mix 2 tablespoons of aloe vera gel with 1 tablespoon of castor oil. Apply to damp hair, leave for 30-60 minutes, then rinse with lukewarm water and shampoo.

These masks can help nourish your hair and promote thickness over time with regular use.