I taught my pony to paw by using the feather at the end of a training whip and tickled the front of his canon until he moved his foot. Start with just getting a response - any pick up of the leg - and then leave him alone and praise or pet. Before this, however, you will want to start with a cue, which for me was just holding the whip out in front of his legs about chest height and slightly wave it up and down - very slightly. We progressed pretty quickly from recognizing when the whip was in front of him to knowing that the tickling was coming and he put together that when he picked up his leg, he was not tickled and was praised. From there he began to exaggerate it himself and we actually were able to move into a crude Spanish walk. Be careful with teaching this trick as you must be mindful that the horse may misinterpret what you are doing at other times and think you are asking him for this response. You want to be sure you don't reprimand him for doing something that might seem like misbehavior while he is thinking he's responding correctly to what he thinks you might be asking for. Always stand to the side so as not to be accidently struck by the front leg. My pony became so sensitive to this behavior that he would volunteer it when other things came in front of him and at times we were nearly hit in the face. He was not being malicious, but is a right-brained extrovert (from Linda Parelli's Horsenality testing) and does everything with exaggerated gusto. So know your horse and be careful.
I did pretty much the same thing, just tapped a whip on the back of the horses cannon bone until the pick it up.
My mare knows how to kiss my face, which is really cute ! I just say 'kiss' or 'can I have a kiss.' taught her how to kiss by holding a treat up to my cheek and when she went to lip at it said 'kiss' and then gave her a treat. Keep in mind that if your horse is really mouthy or a biter this is would be a bad trick for them !!
I also taught her how to hug pretty much the same way, just standing next to her and holding the treat on my hip. We don't do this one as much though, because one time she grabbed my pants and tried to pull them down haha