Shamanic knowledge are often refereed to as simply being a series of techniques. Michael Harner did some interesting work putting together what he dubbed as Core-shamanism, and later "Core" started to become synonym with western Shamanism. But not many seems to understand that this was his version of Shamanism. Not Shamanism per se or in itself.
I find Harners initial work to be the most interesting. The source of his knowledge came from work with Entheogens. In particular Ayahuasca. And it's a strange world we live in where many western core-shamanic practitioners strongly objects to the use of magick herbs but at the same time doesn't seem to realize that their own lineage and source of knowledge comes directly from one mans key to power originating from the Queen of Entheogens: Ayahuasca. ..But never mind.
Western shamanism have some other interesting characteristics. When asked, many practitioners describes their shamanic adventure as: "a series of techniques with the primary object as to create an ecstatic experience." I think this is an adequate external description of much Shamanic work. But this does not in any way accurately describe what Shamanism can be to a person.
To describe shamanic work as simply being a set of techniques is to describe the Japanese word Bushido as simply being: "sword fighting" - because this is what it looks like from the outside!
Shamanic work should never be so intellectualized as simply being a set of characteristics. With a description of Shamanism, somehow you need to accompany the naked explanation with something more.
No one can sum up every ones shamanic work into one sentence, but you can convey clues to your own experience of Shamanic power.
To understand Shamanic work you must also work extensively with the spirit world. And rarely can you work with the spirit world with the only knowledge coming from your own particular spiritual viewpoint.
You are free to think whatever you want, but if your own prejudice gets in your way and are blocking you from seeing the reality of things. Then you might end up getting hurt, and this will only be because of your own stupidity. The spirit world is much like the ordinary world. It has good and bad in it. People are sometimes trying to deceive you, but then again they often behave as friendly and curious of you as you are of them. Don't be judgmental when working with the Spirits.
There is also the question of knowledge. Without a teacher you'll end up working and trying things out for yourself. You need helping spirits to guide you.
But without a teacher, you should also read up on other paths of knowledge without prejudice. The teachings from Buddhist, Zoroastrian, Hoodoo, Gnostic and magical schools like ceremonial or chaos magic will help you. Together with a curiousness for the mythological, esoteric, extraterrestrial, the occult and the outright strange..
(A quick sidetrack: I encourage people to do research outside of the wikipedia.org domain. Much to everyone's dismay, wikipedia is currently being overrun by people spreading disinformation. It's an outright edit-war sometimes and the other side is winning. So you need to go somewhere else.)
The biggest single obstacle for the western mind is the mind control in our culture. And I do not use this word lightly. You are under a spell that has its primary source of power coming from your own social upbringing and mainstream religious belief systems.
A person can go insane trying to fuse together first hand magickal knowledge with the outright lies and stupidity that you have learned from mainstream religion or science. So beware, and don't think that you know to much. A good teacher always first un-schools the student from stupidity, and only then, if the student show signs of being able to learn something should he proceed. Otherwise both parties are wasting their time.
Shamanic practice is not a science. There are no obvious rights and wrongs. And you only know if its right, if it's working.