My default is a simple T-shirt with jeans, and this certainly would be a default. But I still like the jeans and shirt. The jeans are probably as light as I would go. I would not wear the vest as part of the outfit and it would not wear the scarf.
Spring/summer Casual Outfits/ Fashionista Trends--Denim cut-off shorts, chambray button up, and brown accessories.--This works for me but I'd swap out the flip flops for another type of sandal. And put a tank under the button-up for when the temps rise.