Focus on the air being 'colder' on the way in through the nose and 'warmer' on the way out.
From head to toe, slowly focus on each part of the body while naming the body part twice.
Notice any points of tension or discomfort without judgement.
Sit with hands on lap, feet planted firmly on the ground. Start with breath focus then begin to focus on the feet pressed against the ground, feel the ground pushing back against the feet, visualise roots going down into the ground planting you.
Can also be done with back against the wall or a tree and focusing on the back. The tree technique seems to be quite common amongst Wiccan practitioners.
Excerpts from psychonautwiki
The biggest problem with defining a meditative technique is that there are many cultural and historical definitions which make different claims regarding the specifics of this subject.
In order to overcome these problems and document meditation as a whole, a simple and usable open source technique and set of information have been devised to define a generalized meditation methodology and its different components. The meditation technique will be presented in a manner that encompasses the culturally specific methods which are consistent across each other. This is with the belief that the subjective effects of the technique will be equal or greater in efficiency than other specific cultural practices.
The most important and universal aspect of a meditative practice is mindfulness. This is a concept which is present in most if not all culturally specific forms of meditation in various forms usually consisting of the practice of some sort of self regulation. It can also be induced as a subjective effect by many psychoactive compounds, but is also primarily and formally something that can be consciously practised and maintained through a set of specific actions or techniques.
It can be broken down into two distinct subcomponents.
The first of these components involves the self-regulation of attention so that its focus is completely directed towards immediate experience, thereby quieting a person's internal narrative and allowing for increased recognition of external and mental events within the present moment. As thoughts come up, the practitioner returns to focusing on their present senses without developing the thought. This is repeated with the intention of quieting the mind.
The second component involves adopting a particular orientation towards one’s experiences in the present moment that is characterized by a lack of judgement, curiosity, openness and acceptance.