I keep a notebook beside me at all times, ok so not all times but a lot of the time. I use it to make notes doodle sketches so I don't forget them. To be honest the notebook one of the mostvaluable tools I have. I've been doodling ideas for countless years. I never know when an idea will come in handy. Those who follow 4mmscaleagonies will know that those ideas are over 25 years old and they're all in my notebooks.
So here's some first jottings about my P87 scheme. Some of the stuff is pretty blindingly obvious but sometimes a statement of the obvious will lead me somewhere else entirely.
1. Small, easily portable. I like to put up and take down at shows with minimum of fuss.
2. Enclosed cabinet, integral lighting
3. Auto coupling "hands off" operation
4. If it's finescale you should show off the features that emphasise this fact i.e have a turnout close to the viewers and be able to see the wheel profiles. IMHO, if you're watching a train go past in profile then its difficult to see that those are finescale wheels on the car. A car sat in a siding viewed end on it would be easy to see the more accurate wheel profile.
5. Fiddle yard - sector plate. Yep, need one of them.
And it just so happens that there is in my vast history of notes and sketches there is a concept that covers much of these points.
But that is for another day...