I have used
Standing meditation or Zhan Zhuang (pronounced Jam Jong) as it is known
in Chinese Chi Gong, on and off for a few years. Zhan Zhuang is not only
a form of meditation but also builds internal energy and will leave you
feeling invigorated and alive, although it can be hard to begin with. It really is too vast a subject to cover here and I would highly recommend The Way of Energy by Lam Kam Chuen for a comprehensive guide to this practice.
Essentially you stand in a posture whilst maintaining complete relaxation and a clear mind, the posture does not resemble a tree, it is the standing still connecting Heaven and Earth that is tree like. It is surprisingly hard to stand completely still for a period of time especially when your arms are held out as though you are hugging a beer barrel. As you get better at this exercise you will learn that it is only your tension that makes you ache and relaxing is the only option to get through it.
Whilst holding the position you will eventually experience tingling in your arms and through your hands as you achieve circulation of chi, eventually you will be able to feel this chi flow down the front of your body, underneath and back up your back, over the top of your head and down your front again. When you feel this sensation you will have achieved Small Circulation of your chi. Eventually you will be able to channel your chi down your legs and into the ground too, your soles will feel very warm, hot even, this is Grand Circulation. So whilst you appear still on the outside internally there is activity, "in stillness there is motion". It's a fantastic feeling!
Below is the sequence
that I use to aid complete relaxation whilst standing in position (the truth is that you can always
achieve a more relaxed state but again it requires practice):
Imagine
light coming from the top of your head (crown chakra) and then dropping
down around you like a veil of light. As it drops past each area listed
below feel the tension falling down through your body towards your base
(feet). My checklist is:
Head feels like it is suspended by a silk thread (connecting Heaven and Earth) Eyes stare 1000 miles ahead (third eye awareness), you may prefer to have eyes closed. Tongue to the roof of your mouth (this allows the circulation of Chi) Drop your chin Hollow/ relax your chest Relax your stomach Pull your pelvis forward Relax your abdomen Breath deeply using the abdomen rather than the chest. Breath in through the nose and out through the mouth, this utilizes the bodies air filtration system (i.e nasal hair) hence the saying in with the good air out with the bad.
Repeat
this at least 3 times. Once you are comfortable in your stance clear
your mind.
From the description above you may well be able to attempt some Zhan Zhuang but as I mentioned at the beginning of this section I'd highly recommend you at least read the book The Way of Energy by Lam Kam Chuen. Below is a Youtube clip that shows all 5 positions of Zhan Zhuang, personally I only use the the first two and holding the second position for about 15 minutes. The guy (it's not me) is doing it on the beach but ideally you should perform this exercise next to a tree.
Note: For further research regarding Zhan Zhuang it is also known as Standing like a tree, Standing post and standing meditation. Master Lam Kam Chuen is Europe's most authoritative figure on the subject.