Mindfulness and mindfulness meditation focus on becoming aware of all incoming thoughts and feelings and accepting them, but not attaching or reacting to them which is a technique used to help achieve Zazen Meditations.
Mindfulness itself is a way to accept incoming thoughts as they are without judgment which helps you live in the here and now much easier.
There are several exercises designed to develop mindfulness meditation, which may be aided by guided meditations “to get the hang of it”. As forms of self-observation and interoception, these methods increase awareness of the body, so they are usually beneficial to people with low self-awareness or low awareness of their bodies or emotional state, and can provoke anxiety, distress, flashbacks, pain, and even trigger substance abuse in people who are very focused on themselves, their bodies, and their emotions.
One method is to sit in a straight-backed chair or sit cross-legged on the floor or a cushion, close one’s eyes and bring attention to either the sensations of breathing in the proximity of one’s nostrils or to the movements of the abdomen when breathing in and out.
In this meditation practice, one does not try to control one’s breathing but attempts to simply be aware of one’s natural breathing process/rhythm. When engaged in this practice, the mind will often run off to other thoughts and associations, and if this happens, one passively notices that the mind has wandered, and in an accepting, non-judgmental way, returns to focusing on breathing.
In body-scan meditation, the attention is directed at various areas of the body and noting body sensations that happen in the present moment.
One could also focus on sounds, sensations, thoughts, feelings, and actions that happen in the present. In this regard, a famous exercise, introduced by Kabat-Zinn in his MBSR program, is the mindful tasting of a raisin, in which a raisin is being tasted and eaten mindfully. (Eating this way by being mindful of each bite and not taking another bite is a good practice for losing weight.)
By enabling reconnection with internal hunger and satiety cues, mindful eating has been suggested to be a means of maintaining healthy and conscious eating patterns.
Other approaches include practicing yoga asanas while attending to movements and body sensations and walking meditation.
Most of the information here is provided by Wikipedia.