I highly recommend The Advertising Concept Book by Pete Barry. I've just started reading it for my next class and I'm loving the content. All juniors should get themselves a copy.
The book says, "The best strategic, creative team is one that possesses a balance of logic and imagination, verbal and visual skills." What I found most insightful about this statement is that these 4 things are skills students can cultivate on their own. I think some juniors in school get intimidated by other students who may have better design (execution) skills. Yet, what Pete Barry is saying is that a creative can expand their ability to think, to ideate, to come up with great concepts by increasing these 4 skills. And any creative student can do this, no matter how good they are in illustrator or photoshop.
More logic? I read this as more intelligence. It goes along one of my previous posts where I said that creatives must be cultural anthropologists. They must be savvy in pop culture, current events, music, books, poetry. Those who are worldly in these areas have a broader knowledge base to pull from when trying to come up with ideas.
More imagination? Start with lessening inhibitions. As we grow up I think we slowly lose the ability to be overly imaginative because we become accustomed to abiding by the rules.
More verbal? Again read, read, read. Expose yourself to fairy tales and fables, biographies and non-fiction, adventure stories and science fiction. Increasing your literary skills and vocabulary will follow and again, give you a broader base of knowledge to pull ideas from.
More visual? Get out and look around. Go to every museum you can find, travel to a foreign country, study ad annuals.
Logic, imagination, verbal and visual. See how none of these is about putting something on paper? It's the ideating you do before you execute that makes for great work.