A spandex two-piece dress with a cinched belt. Original has three cutouts and a high collar and it helps to prompt these. (Or experiment with prompting and see what you get —usually some sort of cutout or plunging neckline.) I cropped the faces out of the training images, but the model had dark skin, which in the Flux lora remained elsewhere in the training pics and tends to bleed over to the face in the lora. So "pale white skin" should be prompted in Flux if that's what you want as well.

The SDXL lora does not seem to have these skin color issues, but some of my character loras don't play nice with it. Cranking up the weight of the character lora to >1 and lowering the suit lora weighting may help. In general the SDXL lora seems to produce the best results at a weighting around 0.7.