The second trick is, again a basic one that all dogs should know - "Down".
Kyra Sundance suggests teaching this trick through luring and, if your dog will follow a food lure, this is a good way to do it. Start with the treat in front of your dog's nose and slowly move it down to the floor. Your dog should follow it and, hopefully, lie down.
Small dogs and puppies have a harder time following the lure as they can easily reach the floor without lying down. For these dogs I reccomend capturing the down. Put your dog in a relatively boring place (either a playpen for smaller dogs or in the bathroom for larger ones) and wait. Don't interact with your dog at all (you may want to take a book). Eventually your dog will lie down. Mark the moment he does so with a click or a "yes!" and give the dog a treat. If you repeat in lots of short sessions your dog will soon learn that lying down earns him a treat and will do so more readily. At this point you can start to add your cue by sying "Down" as your dog lies down.
Here are Kota and Sparky and "Down":