Immediate Remedies to Judgmental Thoughts
I have this problem myself  but it is getting better. The first thing I do is to spot the first movement of the mind toward judgment and I send the person metta (May you be well, happy and free from suffering).  This then changes my attitude to a more accepting and more opened mind. One other thing which I find helpful is to remember their faults are mine, I have a potential to do what I disapprove and judge. This brings me back to earth and to a forgiving attitude.