1. My big toe must not be separated from the other four. They like to stay together.
2. They must be flat. I only wear sandals in nice weather, so I'll want to be comfortable walking, not trying to balance on stilts.
3. They must be slip-on or zip-up only. Nothing fiddly like buckles or straps or laces because if it's hot enough to wear sandals, then I'm hot enough to get irritated.
And to add to the joy, me being a size 9 makes every shoe-shop a crazed treasure hunt.
Office Papaya Tan Leather Flats
Red Herring Gold Sandals
Unfortunately I found the gold ones first and lost the auction, and I found the brown ones too late, after I already bought a pair that weren't as nice. Oh well.