There are no rights or wrongs to the Shamanic belief system. I only have ideas about the way I see it, and will put on this page how I view it with me being of the Wicca/Pagan faith. Power animals are usually not used by Wiccans or Pagans, but I do use them. I hold value in my Native background and belief systems and enteract them together IE; The Eclectic Witch. Usually Power Animals are used just by Shaman, Tribes, and Native American. Now, as far as Witchcraft, a coven might have a Power Animal which is only known to the group. I use my Power Animal to merge as one when reaching my astral plains, this can be called Shapeshifting also.
The actual term is Shaman with the female version being "Shamanka." These names come from Siberia but Shamanism is practiced around the world. Shamanic practices are generally held within the person who is practicing it. There are no 'churches' or gatherings. Shamanism is the energy that flows through each and everyone of us.
Shamanism has a form which is called Ecstatic. The Christians would say that it feels like 'the feeling of the 'holy spirit.' It is the feeling that one gets when they are so 'in touch' within themselves, it becomes rather 'orgasmic'. It is a feeling when you can journey to the outer limits of your being and 'see' things that are at a higher level ie: hence astral planes.
Just like other Magick forms, so does the Shamanic form. You learn to control your own being and your own energies. Some would say that you can bring harm or 'ill will' to others with Shamanic practice, but myself being of the Wicca/Pagan path choose to keep mine ALL positive, afterall how does one meditate and use their prayer if they hold ill regard for another? I could not go into my stance of meditating with a clear mind if my head is full of 'wanting to get even' or to use my Magick for un-positive things.
Now, lets get going here. How I start to reach my Shaman powers is to find a nice quiet room, this means get the kids out, put them down for naps ect. Some people like background music, some don't, depends on how well you focus. I light incense and use 'atmosphere music' myself. Next meditate yourself into your inner being and outer realms. I use my Power animal which is the Wolf. I simply focus on what a wolf would be like in it's everyday life. Once to your realms of your inner being, I simply stay in my state until I feel like I have reached my goal of inner energies and Magickal abilities. I can not tell YOU, the reader, when or how you can use what I have put here, it all depends on what you are seeking, and what you believe in.
There are two types of shapeshifting. One, is like what I stated before, where you meet your Power Animal, and become one with it on the astral level. The other is where the Native Americans believed that you can change your physical form on the earth plane. Shamans are said to be able to change their physical self into their Power Animal thus becoming one. Some humans have been known to become possessed by their animal spirit and although they may not 'become' that animal, their bodies and voices take on their Power Animal features. These Power Dances are not in anyway scary or harmful to anyone, but I believe they should be done with total knowledge of yourself and what you are doing first.