As an example, on double chin #2 I used PhotoImpact and the Lasso tool to create a "smilie" shaped selection from skin on the neck, then dragged the selection to the double chin area. I cloned over the creases.
I Merged the layers and went to
PS 6 and used the Liquify tool to slim out the neck.
Back into PI, I made a selection of the added bits of skin and added a wee bit of noise.
This is a very quick fix, but with time it could be done quite well.