Our old shed was falling down and not very functional. We set ourselves a deadline of mid-July for replacing it, driven by the desire to look nice for the garden walks.
For a couple of months, we pondered solutions: scratch-built using roofing leftover from our house? An open bay for recycling bins? Built strongly enough for a roof garden?
Ultimately, time and expense brought us down to this 7x7 unit from Home Depot. It'll serve us for many years; perhaps the most important part is that I am carefully layout out what goes into it, so that everything is accessible without moving anything. I'd let the old shed become a bit too full, as a result of which it was hard to get at things - ironically perhaps, putting more things in a shed seems to decrease its functionality.