Observe Without Judging
Avoid putting value judgements on things. Instead, learn to objectively observe reality as it it without ego or emotion. Focus on what you can control, which are your own thoughts and reactions. As long as something does not impair your functioning, your thoughts and how you react to things are in your control. This is a core principle of stoicism that also applies to learning new skills.
The first skill to learn is the art of letting go the human inclination to judge ourselves and our performance as either good or bad... What I mean by judgment is the act of assigning a negative or positive value to an event... The umpire, here ironically called the judge, doesn't judge the event as positive or negative; he simply sees the ball land and calls it out.
Learn to objectively observe your thoughts and your performance from a third person perspective, without judgement. This applies for both good and bad judgement - just observe and notice. Create space between receiving information and formulating a response. Acknowledge your thoughts and sit with them, eventually letting them go without judgement.
I have said that this recognition should be done without judgement: both feelings of compassion and irritation should be welcomed, recognised and treated on a absolutely equal basis, because both are us. When we are possessed by a sadness, an anxiety, a hatred, or a passion, or whatever, we may find the method of pure observation and recognition difficult to practise, in which case it is helpful to turn to the method of Meditation on a Fixed Object, using our very state of mind as the subject of meditation, as this meditation reveals and heals.
This kind of self-awareness is important not only for ourselves looking inwards, but also looking outwards at others. Try not to place value judgements on other people, but rather just observe what they do. See reality as it is without ego or emotion.
References
Meditations by Marcus Aurelius
The Inner Game of Tennis by Timothy Gallwey
The Miracle of Mindfulness by Thich Nhat Hanh