Are certain diamond shapes preferable for certain types of jewelry?

[cakegirl]

I know the majority of diamond talk concerns rings, but what about other pieces of jewelry?
The next two items on my list are diamond studs and a pendant set in platinum. I really love both asscher and oval cut diamonds.
Would asschers be wasted in earrings? How would you use an oval?

Do certain fancy shapes lend themselves to certain pieces of jewelry?