Another river feature you will certainly encounter is a pillow. This feature is caused by water piling up on a boulder. As with all rocks, you generally lean towards them to lift the upstream edge of your boat out of the water. Here is an excellent example from the Gauley called Pillow Rock.
Rocks come in all shapes and sizes. Most of the time, we try to avoid rocks. When rocks have a large flat profile to the current, we can afford to get closer to them and plant a low brace on the pressure wave edging the downstream side of our boat down and towards the rock wall. Large rocks that have a narrow profile typically don't build up a pressure wave. We need to either avoid contact or run a foot or two to the side - especially if there is a large hole below. The water runs fast alongside the rock forming an eddy line. Aiming for the downstream bottom of the rock on a 45° angle with some speed will make it easy to catch the eddy behind the rock. In the picture on the right, you can see a very clearly defined eddy behind the midstream rock.