To err is human.
Everyone makes mistakes.

A slip of the tongue.
A mistake made in speaking.

To learn the hard way.
To learn through experience, often from mistakes.

To hit a snag.
To encounter a problem or obstacle.

To make a mountain out of a molehill.
To exaggerate a minor mistake or issue.

To throw in the towel.
To give up after making mistakes.

To learn from one's mistakes.
To gain wisdom by reflecting on past errors.

To be caught red-handed.
To be caught in the act of making a mistake.

To bite off more than one can chew.
To take on too much responsibility, leading to mistakes.

To err on the side of caution.
To be overly cautious to avoid mistakes.

To make a blunder.
To make a careless or stupid mistake.

To play with fire.
To take risks that could lead to serious mistakes.

To miss the boat.
To miss an opportunity due to a mistake.

To sweep something under the rug.
To hide a mistake or problem.

To learn the ropes.
To learn how to do something, often through mistakes.

To take a wrong turn.
To make a mistake that leads to a bad outcome.

To burn one's bridges.
To make a mistake that eliminates options for the future.

To face the music.
To confront the consequences of a mistake.

To pay the piper.
To face the consequences of one's mistakes.

To walk a tightrope.
To take risks that could easily lead to mistakes.