How do you get 'ears' when baking bread?
In my somewhat limited experience you have two things that affect growth of the crispy ears. As Caleb mentions using a lame to score your bread means you can cut with a bit of an angle that will promote a little flap.

The second is ensuring a rapid oven spring, which will cause the flap to open as much as possible before the starches on the surface set. The key to good oven spring is having a hot enough oven (preheat longer than you think you need to if you are using a stone or other heat-storing vessel in the oven), and a source of steam injection. A few ways to do get some steam:


When you put the dough in, pour a 1/2 cup of boiling water into a small cast iron skillet pre-heated in the oven.
Spritz the walls of the oven with water when you put the dough in.
My favorite - preheat a large dutch oven, and put the dough inside the dutch oven (lid on) to bake. For the last 10 minutes of the bake, remove the lid. The dutch oven stores some of the initial steam release and makes for much nicer spring and crusts. Of course, only round bread fits.