Always make a link between journeys + the layout/lines of the picture leading the responder's eye to focus on something, reach a certain conclusion, implying a journey (especially if its an imaginative journey weee). It's a giveaway kinda thing I use all the time, and it's a good starting point.
sorry that's not very coherent but you probably know what i mean :nods:
also, maybe use of colours and shapes, e.g. angular vs softer pictures, real vs surreal.