Hung and hanged are both past tenses of to hang, which is what makes them confusing, but they have very different meanings.
Hung is something you did to inanimate objects. She hung all the old familiar pictures in her new apartment. She sent the curtains to the dry cleaners, then hung them back up. They hung garlands on the Christmas tree.
Hanged is something you did to a person; it is synonymous with lynched. The court sentences you to be hanged. The prisoner hanged himself in his own cell.
To say a man is well hung is to admire certain of his natural endowments (in slang), while to say a man is well hanged means you are glad he has been executed.
These are definitely words we want to keep straight.
P.S. All this reminds me of a favorite poem, by A. E. Housman. Mom used to pay us to memorize poems and this one was probably worth a whole quarter. (Okay, we're talking the 1950s.)
Loveliest of trees, the cherry now
Is hung with bloom along the bough,
And stands about the woodland ride
Wearing white for Eastertide.
Now, of my threescore years and ten,
Twenty will not come again,
And take from seventy springs a score,
It only leaves me fifty more.
And since to look at things in bloom
Fifty springs are little room,
About the woodlands I will go
To see the cherry hung with snow.
All the cherry trees I ever met were wearing pink, but I think I may have seen photos of white cherry blossoms...??? Never mind. Hung is the point, hang it all!