I REALLY like this video on teaching a dog how to "Sit Pretty" and how to advance it so you can do it with a bit of distance. She goes into some detail about how the Sit Pretty trick can be very beneficial to help strengthen the muscles around the spine, and help protect against injury. She also goes into the importance on proper positioning of the dog- which a lot of us do not think about- but is VERY important.
Again, I personally would not use the clicker, but instead I would use a Marker Word like "Yes" "There" or "Good". As clickers can make dogs (yours and or dogs around you) sensitive/scared and it is really nice to not have to carry around a clicker all the time. But this is totally up to you! Eventually you can do this trick on objects.