Like Deborah said, they go with most things. I think they have a similar appeal to ballet flats, so you could wear them as an alternative for those kind of outfits. Wide-legged pants are one of the exceptions, as they require a less dainty shoe.
[can't see your pic-it's a red X] I like the look of a fitted Tee tucked in, or a looser one perhaps a bit on the long side, left out. But if it's too slouchy, you run the risk of having the same 'shape' on top as below-something I avoid myself or I risk looking like a marshmellow. You could also try topping your current tee with a blazer or jean jacket and see if that helps the proportion and look. I think a high strappy sandal looks good. What else do you have now that might 'go'?

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justpeachy - With harem I always contrast top and bottom, don't wear big loose on top with loose on the bottom. I wear mine with tight vest top and cardigan: sorry to put an annoying pic of myself in this (hope I'm allowed!)
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