i do both. and i do it with shoes too. i tend to find one thing i wanna wear (sometimes a jacket, sometimes its a bag, shoes, cardigan, necklace, lol whatever catches my attention) then ill coordinate the outfit around that one piece. today it was a black tuxedo style vest
I usually have an idea of one item that I wanna wear for the day and coordinate everything around it.
Mostly around my shoes, then bag -- It depends on how much I have to carry around for the day, or how much walking I'll need to do.