to control speed. Port side is going to be tougher because if how the boat going to steer. Practice and taking it slow are key.
I've found if you have room to come to the dock on the starboard side at a 45 degree angle, as soon as the bow gets close to the dock, you can align the boat by putting it in reverse. The prop spin will turn the boat into the dock.
If you are pulling into a slip, my only advice is to have some boat hands at the corners to help guide you in so you don't hit anything.