I think it's important to remain playful about life. To quote the book Finite and Infinite Games, by JP Carse:

"To be playful is not to be trivial or frivolous, or to act as though nothing of consequence will happen. On the contrary, when we are playful with each other we relate as free persons, and the relationship is open to surprise; everything that happens is of consequence. It is, in fact, seriousness that closes itself to consequence, for seriousness is a dread of the unpredictable outcome of open possibility. To be serious is to press for a specified conclusion. To be playful is to allow for possibility whatever the cost to oneself."

Just a few random thoughts:

Feed yourself nutrituous food, not frozen microwaved garbage.

Consume intelligent, thought provoking material, not social media nonsense and battles within the comments.

Keep your self talk at least neutral, hopefully positive (nice man! That sneaking suspicion you have that you are awesome is possibly true)... but definitely not negative (you failed and honestly, you deserve it).

Make time for yourself and use it wisely... aka dont drink alone by yourself, instead work on your portfolio or another certification. Something constructive instead of destructive.

Take time to recharge, get a massage, meditate, listen to music, whatever replenishes the tank.

Celebrate your wins when they happen, however rare.

Be nice to yourself, try and like yourself, have respect for yourself. If it's not there, consider changing to eliminate the parts you dont like.

I try to remind myself over-and-over that I am finite. If I am not mindful about this I tend to push myself too far and pay a price for it.

If I am going to be at peak performance or close to it, I have to make sure that I am properly rested, properly fed etc. and I can ignore these signals for a lot longer than is sensible.

In the long run it does not pay off.

The benefits of regular exercise is another important thing that I pay dearly for when I do not stick to my routine.

If I’m exhausted and spent, I practice self care by canceling plans and taking extra time to relax and recharge.

If I’m stressed out and restless, I channel that restless energy into doing some chores, working out, or taking a long shower. I’ll feel better after crossing some of those things off my to-do list.

On a day-to-day basis, self care is synonymous with generally staying on top of my life. I do my work, I cook meals, I keep my living space tidy, I take my medication, etc. The goal is to minimize the risk of becoming stressed or exhausted later, if I can help it.

Cartoons. I start every day with at least a half-hour, preferably an hour, of something silly that makes me laugh.

Maybe I watch while on an elliptical, or maybe curled up with blankets, but starting my day everyday with something nice for myself helps me get to sleep on time and not immediately drown in anxiety on waking.

I turned my productivity routine into a self-care routine (profile, Task BATL or Whole Productivity). Feels way better this way and I still get everything done, or more if I'm not careful.

martial arts. gets me away from the computer and gets me moving