oh I also wanted to share an idea from Ianto Evans The Hand Sculpted House, A Practical and Philosophical Guide to Building a Cob Cottage
It is a book on natural building but has a lot to add to the design of any space, especially small ones.
So the authors talk about spaces as verbs instead of nouns, for example "kitchening" instead of "Kitchen". I find that I use this idea when I am trying to come up with a design because it helps break me of the idea that a small space is composed of independent spaces the way a regular house is. Thinking of the activity’s in a trailer as actions helps create interconnections between the different uses and modes.
The mock up I just shared was built for "desking", then evaluated from the perspective of "kitchening", "entertaining", "unwinding", etc...