This is almost an oxymoron. If you are focused on avoiding something, all else recedes to the periphery of your mind & senses, and as a result of that, mistakes are exponentially more likely. Yep. Not useful.
Think about the following....
Do you set out to avoid mistakes as a core goal, or do you set out to play with heart, and just enjoy what you have practiced so sincerely for? Do you believe that mistakes are a legitimate foundational part of learning (anything)? They are. They teach all of us, and continually, from student to professional.
What does “mistake” mean to you: by definition in your musical experience? (In both learning mode and performing mode.)
Is it a negative judgement? Or, do you come from a place of wisdom which allows you to let it go, instantly?
Is it even humanly possible to make it through a tune, or piece of music with zero mistakes?
What is your reaction to a mistake, during and after it occurs? Why???
And here is the big one: Who cares about your mistake, and if so, what are the consequences?
These questions need to be put on your Deep Dive list, as an adult student musician of any music style, genre, instrument.
We bring so much conditioning, perfectionism, expectations, mind-driven logic, into the adult learning experience. And we are used to doing and learning “our way.” Most of this is counter-productive in the music realm. ‘Nuf said.
Embrace Beginner’s Mind. Google this if you don’t know about it :)
Like all musicians, I have been in a relationship with mistakes from day one, in my third-grade beginner class. Mistakes stunned and disoriented me. My teachers did not address the relentless nature of mistakes... and so for years even as I successfully avoided them, I did not accept them gratefully as an organic part of learning.
I have evolved as a player and person since then and have the skill to mitigate almost any “mistake,” before or during the active part of it. I also know in every cell of my body that:
There is no such thing as 100% mistake-free playing, on the average. Recordings are highly edited, BTW.
Unless we are in a competition or performing professionally, our mistakes mean nothing to anyone 99% of the time. And, it’s most likely no one can hear you, especially in a group! or know your music.
Music is not about you. Music is about the music. Do your best to be prepared, and then just play for and as yourself, with soul, gratefulness, and in self-transparency. Then, you are about the music, the correct orientation.