Being judgemental is generally not something we aspire to be.
When judgements are directed towards others, they're usually thoughts of criticism and attack, and when they're directed at ourselves they're self-criticism and resisting what is.
Usually a pointless waste of our energy and undermining our (and others') personal power.
However there is one aspect of our judgements that I find useful. And that is the information they can give you about yourself and what's going on under the surface of your conscious mind.
You may have heard the saying that when you're pointing a finger at someone (i.e. judging them) there are 3 fingers pointing back at you.
This means that the judgements you're making aren't really about other people but about yourself.
They are pointing out places (parts) within you that need to be healed.
Usually that's parts that have been deeply repressed, but because they want to come to light, and be part of your life, they let you know this by triggering you through someone else's behaviour.
You may never have looked at your judgements through this lens, because how could there be a part of you that has anything to do with a mean colleague who is always taking credit for your ideas, or that angry person on your way to work shouting into their phone.
You may feel self-righteous about judging them. They are behaving the way you'd NEVER dream of behaving.
I hear you. And I'm not suggesting that you would or that you should. (although if you search your memory, can you find an instance when you 'slipped' and behaved in a similar way? Just asking, not judging here. )
What I am suggesting is that we have a 'shadow' side to our personality. And in this case shadow doesn't mean dark, or negative, it just means hidden, out of sight, unconscious.
It's not that it's bad, it just consists of the parts of you that you never claimed as your own, because during your growth and development they weren't encouraged. That's why your view of them (or wider cultural view of them) is that they're bad.
So these parts of you were repressed, and remain hidden. They only occasionally pop up. Or maybe they never do, but you sometimes wish you could have a little of their core energy (for example that assertiveness that would help you set healthy boundaries, or that confidence to speak up for yourself). Of course you're not aware that that's their core energy, because on the surface such parts look purely bad and useless. So we tend to push them further away still.
But I believe that all parts of us are neutral - they all have a core energy they operate from, and when used constructively, they can be useful and helpful. (Even Inner Critic if seen with compassion and integrated into our life can transform into a constructive critic who is a real ally!)
The key in the process is not to demonise parts of ourselves but see them as contributing to the richness of our life experience, and doing their part to protect our vulnerable core (our Inner Child).
And the same process is happening within other people. Once you understand this, compassion is much more possible.
So this is one way to learn from judgements - when you make negative judgements of others.
There is another way to gain valuable information though, and this is when you make positive judgements of others.
When you admire others so much that you put them on a pedestal, and feel inferior to them, wishing you could be that way, the same principle applies.
The energy or quality that you're recognising and appreciating in the other person (for example confidence, charisma, or courage) has not been acknowledged within yourself. Perhaps never before, so you aren't even aware that it is a part of you that wants to be heard and experienced. It is within you though. All it takes is accessing it - and then learning to invite it into your life more often, consciously.
We're living our life in a semi-habitual way (depending on how much energy we put into developing our self-awareness). The way of our habitual response is based on how self-aware we are. Those parts of our psyche that we identify with are visible to the world (and ourselves) and we think this is all we are.
However invariably there's more to a person's psyche than a limited set of selves that play out in most of our daily life.
We have a whole reservoir of energies, selves, or voices (different terminology, same concept) within us. Once we know this, we can start to consciously access them, learn about them, and integrate them into our life.
One fail-proof way to get an indication of what to work on first are our judgements, positive or negative ones.
So mind your judgements as they're showing you information about yourself. And if you want to detox from judgement, go on a diet of self-exploration. Once your awareness and experience is expanded, your judgements will fall away.
I hope you found this useful, and will see your judgements through a lens of self-exploration from now on. As I often say, life gives us infinite learning opportunities if only we recognise them as such.