We ALL go to YouTube videos to learn everything under the sun...so why not posing too?  

Actually, I think they are a terrific resource for getting a general idea of what to expect and how to do it.  But, I have found consistently with almost all of my clients, that what you see does NOT translate into what you are able to do.  Expert guidance for the step by step AND all of the nuances that give you amazing stage presence is the true key to looking like a natural.