I wish I had these kinds of problems
Buzzzzzz wrong answer
I think nicknames for friends can be endearing, even if they sound a little odd -- that's if the person is OK with it. For instance, you may have a friend who is always late for appointments, and your name for her/him may be "Tardy". Consider the possibility the person may be insulted by the name because it brings to mind they're never on time. "Hey Tardy, you want to go to the movies this weekend?"
If you're so unsure, then don't do it.