Skinning is skinning...there are no different kinds of skinning. Perhaps I am not reading your question correctly.
There are different types of skins you can get, which vary depending on the level and/or type of mob skinned. If that is what you were referring to, I'd say you would probably want to look in your server's AH in hopes to notice demand trends. That will get you pointed in the right direction with regards to what creature type/level to skin.
One more thing --> If you do notice a certain type of skin selling real well, thotbott that type of leather/skin to see what creatures "drop" it when skinned. I hoope that answers your question.