Basically Your Design !
A shed may be as simple as a structure made with plywood sheets through to the extent of a tiny house. What I will say is that what you cannot see, is equally important with respect to the quality of the build. Here is an example showing details, (and why) that may be done to elevate the quality of a “shed”.
Foundation Floor, untouched soil (no movement), edge footings (weight support), Form rises along the back (keep wood 6″ above ground level because the ground is higher behind)
Cement poured with mesh (increase strength – holds if cement were to crack),, anchor bolts (secure building to cement), lower section so make floor closer to ground for lawn mower
Roof covered in PT plywood and sealed as per building code, despite I will be covering with solid 2×10 for overhang for appearance/strength
Building wrap (moisture protection), strapping ( air flow – moisture protection), black metal screening on bottom (moisture and insect protection). Blueskin seal on top (moisture protection) of 2×10 solid roof for extra strength/protection.
Exterior 2×8 Pine Tongue and Groove (strength/visual appeal), showing 2×10 overhang for roof (strength)
First coat of shellac based Zinsser over knots so they will not bleed through paint
Second coat of shellac based Zinsser over knots so they will NEVER bleed through paint
final coat of Zinsser primer (non-Shellac) to protect the wood
Customer’s colour choice sprayed 100% over all edges/seams.
Drywall on back wall because within 2′ of property line, tile floor in center section using leveler/spacers.
pine T&G throughout center section – READY to turn over
  12x21 Cedar Board and Batten Shed  12x21 Cedar Board and Batten Shed  12x21 Cedar Board and Batten Shed  High windows to allow natural light into shed, while not blocking the wall for storage. |   Dutch door on potting shed end  night lights  ceramic floor, pine tongue and groove walls  pine Tongue and Groove ceiling matching walls  Utility storage end  Fancy Shed - Pine T&G inside/out - Practically a Tiny House |   The inside True 2x6 Cedar Tongue and Groove boards are the same board as the exterior.  8x8 Cedar Shed made with true 2x6 Tongue and Groove boards, cedar shakes  12x22 Cedar Deck made with 2x10 boards planned and routed
8x8 Cedar Shed made with true 2x6 Tongue and Groove boards |
  plywood and large shelves  interior lined with plywood  8x12 shed |