'You' are always channeling consciousness. As a matter of fact, it's all consciousness. So who is channeling? Who is being channeled? The only thing that could possibly be channeling is the physical body--channeling the expression of the soul, aka pure consciousness.
What we call channeling is actually consciousness experiencing itself as having many different qualities.
Most human beings on this planet identify with their physcial body, meaning, they subconsciously believe that the physical body is is the totality of who they are. This belief gives birth to many others, one of them being the idea of 'channeling'.
Because most people (who are 'spiritual') believe that they are the physical body, they believe that their realm of influence is limited to the physical body, and no further.
Consciousness is One, and Infinite, but it experiences itself having many different qualities, influences, and forms.
So a 'person' (consciousness identifying with the physical body) can be surrounded by an unseen 'person' or 'being' (a consciousness of a particular influence or personality), and the physical person can allow this unseen being to use the person's physical body in some way--through thought, writing, speech, or the unseen being may use all of the faculties of the physical body.
Remember, however, that there is only One Consciousness, and everything is an expression of that consciousness. Even though the physical body is consciousness too, without the spark of life (soul) to drive it, it becomes lifeless. So if you are 'alive' (the soul is driving the body) that essentially means that you are already channeling--or, a better way to put it--you are being channeled by the physical body.
Just as a spaceman puts on his gear in order to experience space, so must consciousness 'put on' the physicality in order to experience physical reality.
All this talk of 'I was channeling' gives a great high (if your channeling a cool being in fully realized Divinity), but it is not special. The physical body is surrounded by an Infinite amount of energies and consciousnesses that you will never notice as a physical being; but there is a way that you can experience 'channeling' more often:
Inspiration and creativity.
When you feel inspired, your awareness expands into realms of reality where higher vibrational 'beings' dwell. Not all of these 'beings' are in your corner, however. Just like human beings, some want to help, some want to hurt (but these are low vibrational) some are indifferent. A Side Note: One key to identifying the kind of beings you are tapping into is shown by your emotional state.
You are always being channeled.