Creation of new models cannot be taught. Latent creative skills can be developed. Understanding how the creative process works can help. The 4 Main Creative Strands I have recognised several common threads both from my own experience and when talking to other creators. The following are in no particular order.
Most creations come from adapting existing examples.
In origami terms, produce a variation of an existing model which has different properties. This stems from the idea that the existing can and should be improved. Several times I've seen new models developed from previous cut models. In origami terms, start with a paper, make a couple of moves then see if the shape of the paper suggests part or whole of a model. Make more moves until something is suggested.