How should a guy compliment a woman on her breasts?

Answer:
He should NEVER comment on a woman's breasts unless he is married to the woman or otherwise in an intimate relationship.
It is considered to be rude behavior and many women (especially the decent ones) will be offended.
Commenting on a woman's appearance can often be mistaken (or perhaps correctly assumed) to be a sexual advance.
Seriously, don't go there!
First answer by Redbeard. Last edit by Redbeard. Contributor trust: 3549 [recommend contributor recommended]. Question popularity: 2 [recommend question].