Develop the dough well, aim for a windowpane test after mixing or after a few folds.
A properly-proofed dough will give you a stronger oven spring, which helps the ear pop up.
Score and bake directly from the fridge (cold proofing overnight).
Use a razor-sharp lame, hold the blade at about ~45° angle to the surface, not perpendicular, and make a decisive and swift slash.
Use a Dutch oven or add lots of steam to your oven for the first 20 min.
