To be honest, it depends on what you're channeling. I find that many people, generally, seem to ask about channeling spirits. That's mostly a stereo-type kind of thing, because of movies that depict seances and stuff like that.

The person is the conduit through which the spirit speaks. To accomplish this, the vessel channels a connection to the spirit, yadda yadda. If you judged it all based on those films and stories, you'd think that was the only use of channeling at all.

You can channel for all sorts of things. When people say "Well, why don't you manifest it?" (I.E. if you put it out in the universe and put intent toward it, it will happen.) That's channeling too.

Keeping positivity up is channeling. Negativity and pessimism is also a form of channeling, but it's more habit-based because it's really easy to become self-destructive in your life-style.

When you channel, you are connecting to something. You can channel nature, creatures, rocks, spirits, technology, etc. You connect and then let it communicate through your perspective. That doesn't mean it possesses you and speaks it, or writes it. It means that that is where your focus is, so your perspective changes to be from the perspective of the target of your channeling.

So, if you were going to channel something like a cut down tree, you might try to align your perspective with the tree's. But doing this, you could perhaps get an associative idea of what the tree getting cut down was like. Perhaps the impact it had on that stump, what resulted from it.