In Zen Buddhism, this type of meditation is known as shikantaza. This is Japanese for "just sitting". And that's the practice: just sitting, still and upright, with no particular aim or intention.
This is a simple, human activity. No training is required. It is not a special technique.
In everyday life our attention is called out into the world; towards the things we want, away from the things we don't want, towards other people, towards the past and the future. We experience emotions and identify as these emotions. We want to change things in the world, getting and avoiding, in order to only have pleasant experiences.
When we sit in stillness somewhere with few outside distractions, attention is naturally drawn within. Now the sensations, thoughts and emotions are experienced as objects of perception. The locus of our self-identification undergoes a subtle but significant change.
This practice brings balance and clarity. In stillness, the energy of our lives naturally returns to the centre. This is not something we do so much as a natural balancing which we allow to happen. And in the process, we come to know who we really are.