Shower

Pay-it-forward to yourself.

Put out the clothes for tomorrow-you in the evening. Vacuum the living room as a favor for dead-tired-10-oclock-you.

It even works on much longer time scales: Lift weights so old-you don’t break a hip and miss taking the grandchildren to the zoo.

Read for 30 minutes before sleep. Not just articles, but a real, paper-bound book. Helps with sleep, learning, and reading comprehension in the future.

Stand on one leg whilst brushing your teeth

Create a sleep schedule and stick to it religiously. Drink more water.

Meditate even if for only 5 minutes

Sing to yourself. You can have a much wider vocal range with just a little bit of practice. It doesn’t have to be anything challenging, even a simple “row row row your boat” is already a nice exercise.
Personally I find it very soothing and it helps me focus when I’m doing something on my own. Plus I love how my voice can sound when I put in a little effort :)

Some kind of sport. It dont have to be competitive/dificult just some exercise. Preferably outside, 150 min per week can make wonders.

Daydream. Take a few minutes, pace around your place thinking about the things you want to do, not need to do. Its amazing what forcing the time to think can have on action, and the changes that can occur that you didn’t think you had time for.

Make your bed each morning. Your bedroom will look more organized and you will have a nice bed to lie down in at night.

Exercise. A little every day will make a huge difference.