It's all about the under things...
I remember this slip dress thing in the 90s. It was not figure friendly. Even if you are comfortable going sans bra (which I like, totally am) there are still other things that need to be taken care of. Ideally in a comfortable, smoothing, effortless and flattering way. That's not asking for too much right?
Well, if you are comfortable going sans bra (hint: the trick is in the fit of the garment, the right tailoring or looseness will eliminate most concerns) then I highly recommend a pair of reusable pasties. They come in a variety of colors, and when you match your skin tone, become invisible even under a white, crepe slip dress. The trick is the material which almost creepily feels like skin, but is light and breathable and moves with your body when on.
When paired with a set of nude high waisted boy shorts (with a little support, sorrynotsorry) you have the perfect underpinnings for what should be impossible to wear, a white slipdress.
Here's my favorites:
Nippies Skin Reusable Pasties in Medium (that's the color, not the size)
Spanx Power Shorty in Light Nude