Daily existential crisis due to my own mortality. Curiously, the sensation of ever present dread keeps me grounded. Coming to terms with the fact that i'm in a losing battle against entropy itself really puts things in perspective.
I'm mostly atheistic and, in my understanding of the world, once my consciousness ceases to be functional within my body, i'll be forever gone. So that's what i center my contemplation of life around. There will be a day which will be the last for me, a thought that i'll have, which will be followed by eternal non existence. No matter how good or bad the things that will come after will be, i won't be able to experience them, even my awareness will no longer be here in any form, the concept of time breaking down because i won't observe it. In short, i have an expiration date, so it would be nice to do what i can to put it off for a bit longer. Furthermore, it's nice to make the days leading up to it meaningful, if i can and feel like doing so.
Framing things like that really makes most things seem rather meaningless and thus absolves me of worrying about the daily minutea too much, or getting too emotionally invested in any of it. For example, right now i'm stuck in the middle of conflicting value systems in my country and social circles. Not necessarily nihilism or even anti-natalism either, just the realization that i have a finite amount of emotion to feel towards the world around me and care to put in it.
DISCLAIMER: the following is highly polarizing and one example of things that i've seen consume people's time, identities and lives. Things that are better to avoid in my eyes, offered as an example. Skip to the end of italics if you'd like to skip this part.
On one side, there is a large part of my current culture that's oftentimes mean, xenophobic, homophobic, transphobic, racist and so on, which would have me act a certain way and uphold both their traditions and stereotypes in some sisyphean pursuit of a conformative national identity, in a world that's becoming more and more globalized and where many of these concepts of old aren't always relevant.
Then there's a different part, which perhaps leans too much in the opposite direction, not realizing how dangerous expressing themselves freely can be in a society where the former group is not viewed as a credible threat, a disconnect between what should be and what actually is, and sometimes just want to react to things purely based on emotion and not explore the finer points and nuance (e.g. how RMS was "cancelled" some time ago, despite possibly not being neurotypical and lacking compassion where some could have been useful), sometimes desiring to break down systems for no good reason.
Then there are the corporate interests which view me and others as expendable resources and members of society that should be freed from their financial burden of having disposable income, and who'll go to great lengths to achieve that, anything from intruisive ads to trying to convince me that i need things which i don't, the greater systems at play essentially ensuring that i'll receive only a small percentile of the income that i actually generate with my work, even home ownership currently being out of reach, as is financial independence of any sort.
I guess i could also throw in organized religion or other groups that exploit people's need for belonging, from social media, to multi level marketing - oftentimes spouting their own values and beliefs as fact, typically with certain non-publicly expressed goals in mind. Groups that would be quick to indoctrinate me in their midst and make me lead my life in better alignment with their values.
On a grander scale, one can even talk about things like environmentalism here. On one side, you have outright denial of what's going on with the planet and a desire not to change anything from how it was, to go far beyond the "business as usual" scenario for the economic and environmental outcomes. On the other, you sometimes have crafty entrepreneurs, whose promises are detached for reality, or activism to the degree where the individual action is far beyond what any human being would reasonably do.
From every side, there are groups of people and ideologies that try to get me to align with what they want me to align with and believe what they say, yet none of those really matter. I'll just tell each group what they want to hear so they don't end my existence or make it worse, and apart from that i'll just continue my life one day at a time. Why? Because after the aforementioned contemplation, there's no reason for me to throw my life away while attempting to follow any of their teachings, nor is there a reason for me to try to oppose them and ruin my life that way.
Instead, i should care about myself first and foremost. Get enough sleep. Eat reasonably healthily. Get some fresh air every day. Do some light exercise. Learn a skill, ideally something both mental and also something else that can be done with my hands. Play with my pets to feel better. Read what i want and entertain myself however i please. Learn something new to put myself in a better position in the future. Build relationships with the people who can make me enjoy a friendship with them. Avoid or cut out those who won't be healthy for me in the long term. Be nice to others so i can feel good about myself, or count on them to do the same. Just generally make existing more pleasant. Don't buy too much into what anyone says, but instead occasionally pause and take apart their arguments and reasoning to see how mine aligns or conflicts with theirs.
My life is too short for me to stress about those things, or to get too invested in social constructs. It is also probably too short for me to reap the benefits from life extension tech or viable cryogenics. Alas, i'm probably born to die. So why not make my life and myself better until then?
So, in short: a form of mindfulness/contemplation that's born out of needing to cope with various stressors in life.