[BobK]

Not so many below the waist. Here are a few:

have a leg to stand on - have a valid case:
"He'll try to argue, but he hasn't got a leg to stand on"

stand on your own two feet - be independent:
"having lived at home until he was 35, he at last decided to stand on his own two feet"

put your foot in it - be undiplomatic/insensitive:
"He shouldn't have mentioned her background - he's really put his foot in it now"

have an Achilles' heel - have one (not necessarily obvious) weakness:
"Superman's Achilles' heel was his reaction to green kryptonite"

put your best foot forward - make a good start (not necessarily on a physical journey):
"She put her best foot forward by making a list of everyone she had to write to"

And another facial one:

stick (poke) your nose in - be interested in someone else's affairs:
"It's my problem - there's no need to poke your nose in"

b