One of the distinct features about the human mind is its tendency to apply judgement to experience. The judging mind has its likes and dislikes, its do's and dont's, the things it desires and the things it tries to avoid.
With mindfulness, we practice doing the opposite of this. That is, we observe our experience without judgement. This means that, in each moment, we observe our experience as it is without adding anything extra to it.
In mindfulness meditation, we simply notice what arises in our experience. This may be a memory, an itch on our body, or a sound in the distance. We also try to notice when judgement arises. For example, we might find that we say to ourselves, 'I wish that sound would stop, its really annoying me' or 'I'm no good at this meditation'. Whenever we catch ourselves doing this, we acknowledge the judgement and return our attention to the object of the practice, such as our focus on the breath.
What this does is counter our tendency to judge our experience too quickly. Whilst judgement in itself is a very natural process of the human mind, it can limit our experience and even lead us into anxiety or even depression.
For example, if we judge an experience to be 'unpleasant' we might never explore it further (even though it might potentially be something that enriches our life). Conversely, we might only chase after the things that we find pleasurable in life and fail to face up to the challenges.
Further, if we judge ourselves too much, we can become very self-critical and limit our own potential for happiness and fulfilment. Think of a time, when you may have said to yourself that you will never be able to do something, will never be good at something, or are not worthy of something.
In every day life, we can practice non-judgement. Try this exercise: next time you are walking down the high street, notice how you may judge different people based on how they look. Someone may look threatening for example. Once you notice this, turn your judgement into curiosity by investigating how this judgment makes you feel and why you might feel that way. Look at the person with interest and perhaps reflect that they may not be like you think, and that they too have friends and family who care for them and who they care for, and that they also wish to be happy. Perhaps send them a blessing and wish them well.