So I added some hooks for hanging bicycles, and a deep shelf in the back. The shelf doesn't go all the way to the right wall, so that I can still lean panels to the wall.
With the studs doubled up and far apart, it's easier to store stuff closer to the walls. I built some shelves for chainsaws. I will probably add more shelves to the walls over time.
And the space below the rafters is already filled with wood! It's just the perfect place to get long stuff out of the way.
I'm glad I built the walls the way I did. With the sheet metal siding screwed into 2x4's and 2x6's, I didn't end up with any screw points sticking through. Sharp points sticking out of walls is just an invitation for nasty scratches!
I spread a few buckets of coarse gravel that I had on the ground. I laid old scraps of pressure treated 2x6s on top of that. I always end up keeping scraps like that, so this was a good way to use them up. But looking through the hedge behind the shed, I could see a pile of used 2x6 scraps behind my neighbour's pool. They had been there for years, and I asked if I could use them. I think he was glad to be rid of them.
I didn't have enough 2x6s to cover the whole floor, so the area under the trailer is just soil and gravel. I see people throwing out patio stones from time to time, so next time I see some on the curb, I'll use them for the shed floor. Cheap things come to those who wait!
My one regret so far - the shed is about 90 square feet, and the maximum allowable for a shed like that is 108 square feet (10 square meters). I should have built it bigger!
Building your own shed certainly makes sense. Sheds made of sheet metal or vinyl tend to be too flimsy and some of the ones on display usually are already broken.
Wooden sheds are sturdier, but if you "buy" a wooden shed, you really just get a kit consisting of pre-cut parts, so you still end up building it yourself. Might as well start from scratch.