I have a couple of big posts coming – they just need to get out of my brain and on to the computer. In the meantime, Janet has a couple of great posts (part 1, part 2) about learning how to be a grown up scientist.
My only thought on this, at the moment, is remembering asking my PhD advisor, who was a great mentor, how he came up with ideas and how would I know that I had good ideas for my own research. I did not get a satisfactory answer and I still have not sorted it out for myself yet.
I also realize that good ideas are not enough, but you also need ideas that can be well presented to funding agents and committees.