Ok I'll admit that I haven't been using this one but here goes anyway:
Click E in the Color Pane and you will disconnect a node without deleting it. This will come in handy if you want to make a bunch of looks that can be accessed later without having to rebuild a new node each time, especially if you are a tidy colorist and label each of your nodes like a champ.
When you're ready to take your keyboard shortcuts further, hit Command + ,