I assume you're talking daily casual use. In summer I'm often out at swim meets, the park, dogs on a leash. Super casual so I use my Kavu a lot. It's also great for short day hikes since it fits a water bottle.
https://kavu.com/products/rope-sling?variant=40083377356871 For the same reason, I also end up often carrying a smaller LL Bean tote in the summer. Washable canvas, holds a range of things.
Otherwise, I use the same leather tote that I carry all year round.
Clearly fashion isn't my thing but summers are active and casual for us so I need a bag that's the same.