Photshop is a fantastic photography application that can do so much.  The challenge with it is that it is so powerful that it can be insanely complex.  There are typically many different ways to do the same thing.  The amount of work to the different approaches to a different solution will vary.  My general strategy is to try to search the Internet to learn about the different ways to solve various problems.  I recently ran across this site which lists many different URLs with tutorials on a variety of different types.  One of the problems I have been trying to fix is double chins.  I found this video on YouTube on that specific topic.