Although I can appreciate the focus of having a favorite mantra in life, I have found myself using numerous and varied mantras to handle moments that come up.
Tired on a jog: One more step. *inhale exhale*
Feeling intimidated by the day: Just keep going.
Seeing a pregnant woman: You are classy. Head up and smile.
Overwhelmed in the middle of a project: It’s okay. Do a little more.
In the presence of women clearly more physically attractive than I: My husband loves and accepts me as I am.
Hearing the pipes connected to our [only] toilet make rather loud noises after flushing: If the toilet breaks/there is a major plumbing issue, you will survive.
This technique can be used by your best self to encourage your less-than-best self, to help keep perspective, to move slightly more gracefully through awkward mental moments than might have happened without the mantra.
I am lovable even when I am not particularly graceful.