Here are some things I am trying to improve with my health right now.
Proper sleep - I try go to sleep at ~ 23:00 and wake up without alarm getting as much sleep as my body needs.
Exercise - I start every morning with some exercise.
Dental care - Brushing my teeth every morning and evening as well as flossing it few times throughout the day.
Skin care - Clean & moisturize my skin every morning and evening & applying occasional face masks.
Ergonomics - Properly sitting, standing and keeping good posture throughout the day. Never slouching my back and sitting at one spot for too long.
3 simple habits that can protect your brain from cognitive decline (2019) - Exercise, IF, sleep.