The grey matter has been gurgling away and I'm getting a hint of a creativity approach that I wasn't even looking for, although I can't quite grasp the idea in full yet. I'm going to post what I've got so far and see if anyone can bounce back any thoughts. As an experiment I'll avoid deliberately working on this germ - I'll think of the idea briefly before I go to bed at night and see what the subconscious mind comes up with.
A starting subject and Google Images
The idea is to choose a starting subject (or perhaps specific context) and then treat a random Google Image as though it represents an idea about that subject. For example, I can start with a subject: the London Marathon, and observe any random image such as this one. I then kind of presuppose/pretend that the image is an idea about the subject - the London Marathon - and present that idea in a sentence:
The idea is that the London Marathon competitors run in groups.
and then use that to generate ideas (perhaps using it as a lateral thinking provocation). My initial idea is that the marathon organisers could group all the people who run a certain time in the marathon - say, those who finished between 3 hours and 3 hours 10 mins. The next year the competitors from that group could race against each other 'in their own race' where the participants would be racing against each other for a prize/pride/glory or whatever.
Subject: The World Cup
With this image I immediately thought of England's trophy cabinet from the World Cup! But here's the idea generated from the image:
The idea is that Fifa generate a single rating based on each team's World Cup performances for the past 20 years (or make it 40 ;) )
This leads to other ideas such as: trophies for best WC performers over 20 years, trophies for the best penalty takers etc.