I made the log store by drawing out plans of how the pieces would be fit together. I then cut pieces to size (the depth and width of my tiny shed), then sanded each piece with an electric sander, revealing a very appealing and characterful wood. I then sourced nails that would hold the slats together (I found 40mm ones were beautiful on a thicker style pallet).
I first built the base and then I attached the sides. To which I then attached the roof using screws. I made the roof by nailing slats to a rod of wood I got for free, but you can easily get cheaply from a DIY store.
I then used two squares of this rod to attach the sides to the back piece (but in hindsight, it may have been better to use metal brackets. All parties and back were nailed to the base blocks, initially.
Used the same rough method I used for the roof to make the shelf with the remaining rod I had left, and adding two extra blocks of the rod parallel to the backset to support the shelf