Always Show the User Library Folder
A simple command lets the user ~/Library always be shown.
This isn’t a defaults write command but it’s very useful if you frequently dig around in that directory, and you may as well make the change while you’re in the terminal.
chflags nohidden ~/Library/
Most of these commands will be usable in all versions of OS X, though obviously things that require something like Mission Control is only going to work in Lion, Mountain Lion, and onward.