Opening a can of worms here, but I'm designing my (realistic) dream shed.
I've got 5 x 7 (2.7 to the gutter) metres to work with, and that's as big as it gets (really!). The shed will be Colourbond trim deck and lined/insulated inside.
The size is basically an extra-deep bay and a half. I've got the F100 and the T500, and the mix will probably always be 1 x project car and 1 x project bike (probably not always something as big as the truck).
I've got quite a lot of tools and do all my own repairs and servicing on both, so I want a really well set-up workshop. As you'll see in the sketch, there will be a compressor in a shed outside, with various nitto fittings from hard line under the benches. The power points will be 15 amp double points. I like the idea of the laundry tub in the corner, good for washing parts as well as cleaning up before I go back to the house.
The main bench at the back will be RHS with a steel top and sliding doors on the cupboards. The fold-up bench will be timber on an RHS frame with fold-down legs, so it can sit flat against the wall when not in use.
The main bench will have a bench grinder, a drill press and a vice permanently fixed to it (can decide positions once it's all in).
Here's a design a mate did in a CAD program:
With bench folded away and pickup and bike inside:

With just the bike:

Yellow = fluoro lights and power points,
Blue = water fittings and laundry tub,
Purple = compressor and air fittings (compressor would live behind the shed in a waterproof pool pump enclosure),
Orange = bench,
Green = rollcab toolbox.
The Grey blocks on the RHS are a personal access door and a sliding window with security screens. The one at the front is a 3 metre roller door.
Any comments about other things I should consider or anything I've missed would be much appreciated. Obviously I'd love a hoist, a fridge, a 60" TV, a cage full of bikini models etc, but I really need to focus on the practicality!
Supplementary info: This shed is in suburban Brisbane (capital city, Australia), will be used (quietly) for tinkering on weeknights, with the odd full weekend of spannering. It's only about 15 feet from the house, so I don't need a shower/fridge/TV/loo.
This should be a fun discussion...
NH