I read alot of books on the second and first world war. My latest dioramas have come from ideas I read and just build up a picture in my mind. I then started researching the subjects. That's when i found pictures, alot on the internet, others in books. I then plan on buying that "one kit" that I'll base my diorama on and plan on the rest coming from my spares box. But it doesn't normally work that way, because I see those other two or three figure sets, some detail sets and then I'm off. That's when the diorama started changing in design and I get other ideas of things to add and new things to try.
I normally wait until I have collected most of the things I want to have before I start building. During the building process, it always changes a little. Sometimes I go way overboard and the diorama takes too long. I then lose interest and start building something easy. I normally work my way back again quickly.
One of the dios I am building is a scene from the movie "Iron Cross". I told myself - "build it exactly how it looks in that split second". So far the tank is done" the ground work is planned and I'm stuck on the figures because I just can't find the right pose! Guess I'll just go shopping!
Good luck!
Jason