I have had botox in the jaw (masseter jaw reduction) and it is very good. The effects are quite subtle but my lower face is now less square than it was before. If you put you teeth together and clench you can feel the muscle at each side of the jaw which will tense up and stick out quite a lot, almost half-ball shaped. Well, mine doesn't anymore as a result of the botox, and as a result that muscle looks a lot smaller, reducing the size of the lower jaw.
You can also use botox on the upper face to raise the eyebrows slightly, which has a feminizing effect, but I've not tried that one yet.
Fillers can also be useful on the lips and cheeks in particular, but I've never tried them either. I have had fillers in the feet (a loub job), which hurt like hell, but so worth it!