I have the same pet peeve as Anderson Cooper which is bare feet in public. I hate it. It so grosses me out especially in New York. Oh my God New York in the summer with people and their feet in their sandals and their flip-flops like get it away!
In the summer I wear shorts with a bright top and ankle boots or just sandals. I'll add a nice scarf maybe a hat some cool sunglasses. It's all about the accessories.
A few years back when my style was 'punk grandma ' I picked up an amazing pair of sandals - orthopaedic ones with really thick soles. I've given them away to a friend now because these days my look is more '1980s substitute teacher gone wild.'