In some classes we teach the fine art of knot tying. Unfortunately, I have not been blessed with the knot tying gene, so I have to work at my knot tying skills. Tonight, whilst scanning around the net (mainly via Stumble Upon) I found some excellent videos in YouTube that demonstrate the knot tying very clearly and simply.
Here is a quick example of the bowline.
Here is a longer video with a longer demonstration and slightly different technique.
Here is an example of the double sheet bend