So, we've all realized by now that peoples' estimates of 25% surface area tend to vary wildly. So out of boredom, I made a to-scale image of a 4'x6' surface which is broken up into coloured tiles, and further subdivided each tile into differently shaded sections. The idea is that, if one were so inclined, one could cover 1 quadrent per tile in terrain for a quick, proportionate, and well distributed table setup. Then things are easily fine tuned by shifting things a bit or breaking up the solid sections.
I was mostly interested in knowing with certainty what 25% terrain "really looks like", but I figured others might benefit.
The finest grid squares are 1"x1", the darker squares overlaid on the lighter are 2"x2". The purple hash lines occur every 12".
The coloured tiles are sized for convenient divisibility. Each quadrent is 8"x9".
...and with 25% filled in: