Most of the time, when scrapbooking, our starting point for a page or book is a photograph - or group of photos.
But sometimes it is a refreshing change to lead with something else. For instance, you could try starting with a colour and then fitting your photos (or whatever) into that theme... that's a bit like a challenge I suppose.
However, as an alternative, why not try using a quote as your starting point on your layout?
Here is a link to a good site with lots of quotes categorised under a large number of headings, for instance, this one is under the "Curiosity" heading which is a good one for children's layouts.
So why not try starting a scrapbooking page from a quote and see where it takes you!