I hearby decree that all women (and men) who wear open-toed shoes shall do the following:
1. Wear shoes that fit.
This means that your toes are not hanging over the side or front of the shoe AT ALL. There is little I find more disgusting than seeing someone's claw-like toes hanging out over their shoe.
I saw a women yesterday who had a full INCH of toes that came past her sandal. NEWSFLASH: The shoes don't fit.
They also don't fit if your heel hangs off the back of your shoe. Or if the sides of your feet slop over the sides of the shoe.
If you have doubts about whether something fits, just put them on and look at the side view in a mirror. Either your toes/heels/sides are contained by your shoes or not.
2. Get (or give yourself) a goddamn pedicure.
Feet must be washed, toenails trimmed, cuticles pushed back, dead skin sloughed off. This is a bare minimum, people. Don't like it? Don't expose your feet to my eyes.
For the love of all things stylish, don't get rhinstones on your toes. A tiny painted flower is (sort of) cute, but little plastic stones are just trashy.
3. Avoid plastic.
I know that plastic shoes are inexpensive, but that is the point. Cheap shoes don't breathe or wear well. I'm not saying they have to be designer sandals (paying upwards of $200 for trendy sandals is freaking ridiculous), but do pay attention to what the shoe is made of, whether your feet will slide around after you sweat in warm weather, if the strap will snap after the second wear, etc.
4. If you wear colored nail polish, immediately remove or reapply when it chips.
Chipped toe nail polish is beyond tacky. If you don't want this kind of maintenance, go polish free or chose a neutral shade.
If you don't wear open-toed shoes, you can ignore all of the above. For the other 99.9% percent of us this summer, these are Words To Live By.