I'm a visual person.  I've tried to join the keyboard-shortcut-cult.  I've tried Enso, Live Desktop, Google Desktop, and just about any productivity-promising app Hanselman recommends.  I love the idea, but somehow never end up using them.  I never can remember the shortcuts, or even that they are there.  But then again, it is Visual Studio, right?  We do have Graphical User Interfaces for a reason.  I'd just about given up on trying, until I learned one humble little keyboard shortcut that all by itself has saved me tons of time in VS:

CTRL + .

Any time you see the VS smart tag on some code, press that.  Don't think, just do it.  It will do your bidding, before you even know you bid it.  Need to implement an interface?  : <interface> Ctrl + . <enter>. Add a using namespace? <class name> Ctrl + . <enter>.  Rename a variable?  <rename> Ctrl + . <enter>.

If you need pictures, here's more: http://haacked.com/archive/2008/06/23/visual-studio-smart-tag-expansion-tip.aspx