Lokah Samastah Sukhino Bhavantu लोकः समस्ताः सुखिनो भवन्तु)
Lokah Samastah Sukhino Bhavantu is a sanskrit mantra meaning
May all beings everywhere be happy and free, and may the thoughts, words, and actions of my own life contribute in some way to that happiness and to that freedom for all.

This is the mantra I use the most, both chanting after my own asana and meditation practice, or reciting in my head. This is also the first mantra I ever had a connection to. In my first ever yoga retreat in Casa Cuadrau, we would chant this mantra and I never wanted it to stop - it completely caught all of my attention and it felt so good.
Before this experience, I found it a little awkward to chant OM after class (yes, my beautiful yoga students, I know how it feels!), I had trouble understanding the use of sanskrit mantras in class as I considered it religious and dogmatic, this started to change with lokah samastah sukhino bhavantu, and now I use mantras and integrate sanskrit words as much as I can in my classes.
I put effort into integrating the yogic roots and yogic philosophy in my yoga classes. This is both to honor yogas roots, but besides honoring, to me it is about sharing the big wast picture of what yoga is and how it can change our world when integrated into our lives.
This was my first ever experience with meditating on a mantra, concentrating on a mantra. It is a mantra I find useful and powerful on a personal level - a prayer, if you like, to be happy and free - and to remind myself to act in a way that contribute to happiness and freedom for all. On a global, or universal level it radiates compassion and deep hope, something we all will benefit of right now, always, but especially right now.
If you want to listen to this mantra I recommend a beautiful chill version of it by David Lurey, here: https://www.youtube.com/watch?v=xn7mhcdAqzc
For reciting, this version can be easier to come into the flow and meditate https://www.youtube.com/watch?v=lBF5Vk2GksE
There are SO many versions to be found, just copy paste
Lokah samastah sukhino bhavantu into spotify or youtube and find your version.