I try to go without a bra unless necessary for shaping or nipple coverage, so sometimes I will wear a bralette instead if I can't go completely without anything. I may also wear a bralette underneath a loose-fitting shirt that has a large neckline; here the bralette kind of functions as a bra that is meant to be seen and is part of the outfit.
I find that the bralettes from Free People are pretty substantial and give decent support for a bralette. They don't seem to squash me down like some bralettes do.
The bralette finds below are from Free People. For some reason, Free People items don't work with the YLF collector thingy, so they are custom finds.
ETA: I'm also adding finds for tops that I wear bralettes with.
The Madewell navy top is loose fitting and can expose me, so I wear the black bralette with it (the bralette is quite substantial).
The white Anthropologie top is very sheer and has a deep neckline, so I wear the halter bralette with it (I have that bralette in navy). The bralette follows the shape of the blouse neckline, so it works nicely.
The Free People white gauze cold-shoulder top gets worn with a white bralette in the style of the red lacy one below (the white one was sold out when I made the find).
The J. Crew white tee is quite sheer, so if I don't feel like wearing a nude bra with it, I will wear the navy halter bralette. Again, the shape of the bralette matches the shape of the shirt's neckline, so it works with the outfit.