Back to the drawing board
So after having my last idea run down, I decided to consider making a crest for each of the postcards, maybe base the design on how much of the colour paper is. As well as looking at the keywords within the brochure, that I could probably base the design on
This picture is of a page from my sketchbook.
I also took another look at words associated with the coloured papers I had picked, to help given me more ideas for the final design.