I'll start with my own rather primitive system.
Basically it is the notebook.
I carry it around with me everywhere,
jotting down ideas and trends I see happening.
Then when the notebook is full
(usually go through at least one a month).
I'll look over the ideas
and judge whether or not an idea will go on my list
(my top 25 ideas).
What puts it onto the list
(which pushes others off)?
The resources needed,
if I have the skillset/interest,
the timeliness of it (do I need to do it NOW?),
the size of the idea,
the capital required, etc.
Having this list has helped me look out
for the resources I need to bring the ideas to life.
In corporate, I would add them to concept/idea screeners.
This not only had the ideas being consumer tested
but brought them in front of the executive team.
In personal, I'd keep an eye out for partnerships
to fill in the gaps I usually have.