To improve your child's overall health and strengthen their immune system, it is important to ensure they consume plenty of fruits and vegetables, get adequate sleep, manage stress effectively, and maintain good hygiene practices. Avoid close contact with sick individuals, refrain from sharing towels, and encourage frequent handwashing. Consider using a saline solution for nasal hygiene to prevent mucus buildup. Additionally, it is recommended to perform nasal hygiene at least 30 minutes before bedtime for optimal results. These non-pharmacological measures can help support your child's immune system and promote their overall well-being.