Be reflective to yourself and others to be clearheaded.

Ask others’ opinions.
To overcome the availability bias, you must ask others’ opinions before coming up with a conclusion or decision.

Keep a journal of records.
Write down your personal predictions and compare them with actual situations.

Remember the reason for your decisions.
Rather than being angry over a poor choice or praising yourself for one that might have only coincidentally resulted in success, remember the reason for your decision. Were your justifications sound and understandable? If you didn't have luck the last time, you'd be wise to continue using that strategy.