I have some CAD skills and am pretty good with Photoshop that I use in my work as a fire protection specialist. I have been hiking since the 60's if you don't count the Boy Scouts. I have made a lot of my own gear, but always use freehand sketches for some reason. When i made a potholder/windscreen recently i made a cardboard prototype out of a cereal box. But a nice CAD drawing would be nice for sharing here. I'll have to think more about that.
Jim M