My aunt gave me this dress several years ago, and I saw in in my costume room just begging to be redone. I basically just took off the collar with my seam ripper and added the belt and I was done. The second picture is the dress before. Please click on the photos to see the whole view of the dress.
Find an old collared dress with potential.
Take your seam ripper and rip off the collar. If you want it to be more polished looking once it's ff, you can sew piping or something on the raw edge. I just left mine how it was & added accessories.