The modestly titled Gil The Jenius blog has a post with some interesting thoughts on idea generation methods:
"In essence, the creative method The Jenius uses can be boiled down to three approaches:
1) "What if?": No boundaries, just what if?
2) The power of AND: The Jenius often refuses either/or in favor of and. Don't choose between two attractive options: do them both!
3) Think "simple elegance": Take it beyond normal limits. Then push it some more. "
That is pretty much my own mentality towards idea generation methods. I'd like to think that in creative activities there are several key principles at work. The ideal is that there would be a limited number of core creative operations for producing good ideas and the results achievable with a 'bag of creativity tools' would instead be a by-product of the core creative operations.