In terms of ambassadorships, the prestigious ones are to major allies or friendly nations and they generally go to major backers (either financial backers or retired politicians with a lot of influence) of the president, these are to places like the UK, Canada, Germany, France, Australia, Japan, Italy and Spain. These are typically “figurehead” posts as there are long-term foreign service people in the embassies who do the real work.
Ambassadorships to places where relationships can get “dicey” (Russia, China, Mexico, South American countries) or potential “hot spots” (Eastern Europe, Greece, Turkey, South Korea, Israel and the rest of the Middle East, India) and the United Nations generally go to people with extensive foreign policy experience.
Stable countries that are American allies, but not really crucial to American foreign policy go to people like Kmiec in return for their support.
I had heard that Kmiec wanted to be appointed to a Federal Appeals Court bench but Obama wouldn’t do it.