Definitely skill is needed. To be honest when you do anything there is a certain level of skill that is needed to be able to do it well and to be able to do it effectively as well. And this is very true in graphic designing. Especially as this is a profession that many study for years to be prominent and proficient in it.I do believe certain level of skill is needed for graphic designing. Only then we can try to make something really good.
Creativity is also necessary to make something unique and good. This is just a personal opinion of mine. I don't have any such skill though.