On Intelligence, by Jeff Hawkins (p.75):

Thoughts and memories are associatively linked, and again, random thoughts never really occur. Inputs to the brain auto-associatively link to themselves, filling in the present, and auto-associatively link to what normally follows next. We call this chain of memories thought, and although its path is not detrministic, we are not fully in control of it either.

 Let's take this passage as a starting point and see how it might help us better understand human creativity.
To generate novel ideas, we have to create out sequence, i.e. random thoughts. If Hawkins is right, and they cannot occur randomly, we might decide to force the seemingly "impossible" randomness by inserting various trigger points, e.g. by emerging ourselves in randomness-rich environments. This approach could be the basis for spontaneous creativity, which many people experience when they come up with a new idea. De Bono's random word stimulation is a good example of a conscious effort directed at creating pseudo-random triggers.

Another approach, let's call it systematic creativity, would be to guide one's mind through a certain sequence of various perspectives that disrupt routine thought-memories. The goal would be to force the brain into thinking at different event scales (e.g. tiny, small, normal, big, large, huge, humongous), time intervals (e.g. instantaneous, quick, normal, long, ..., eternal), and etc. By breaking through the "normal" path of auto-associations into the direction of strange, but possible, associations, we can imagine and explore virtual environments rich in novel possibilities.

We know that inventions, especially the good ones, create new worlds. Therefore, a conscious, systematic effort to envision and play with dimensions of a possible world, should be very beneficial to creativity.

Reference: Jeff Hawkings with Sandra Blakeslee. On Intelligence. - 1st ed. Times Books. 2004. ISBN 0-8050-7456-2.