Bags are one of the first things I notice about people's outfits, especially in the colder months. I like my bags to make a statement but still serve a function. For example, most of my winter coats are neutrals (charcoal grey, heather grey, taupe), so I feel a bag adds a splash of color. But in the wnter, it needs to be large enough to toss my hat and gloves in at my destination. I do walk a lot and take transite, but even when I drive, I carry a bag out to dinner or to meet friends, or even things like grocery shopping, so it does get "seen," so to speak.
In the summer, my bags tend to be smaller and more utilitarian. Don't need to fit all the winter accessories and I spent more time out of my house (festivals, walking, etc). I like neutral ones to wear with bright colors and colorful ones to wear with black/white.