For me I can't bring myself to build districts if there aren't any good spots for them. I used to hate making Theater Squares because it was mostly impossible to get decent adjacencies for them without wonders, but now they at least have the Entertainment Complex major adjacency which allows me to make them now. Commercial hubs are still a problem though, as they just have rivers and the harbor, which is rather limiting.
I guess it's not exactly aesthetics, but it does cause me to play suboptimally for the sake of pursuing a specific ideal.