Design is such a bizarre thing; it's easy to think that the more visually satisfying—i. e., pleasant to look at—something is, the better "design" it is. Yet, in the end, design is very seldom the subject. In the vast majority of circumstances, there's someone else under the spotlight.
Hence, what good design should be doing is being that spotlight. What you want, ultimately, is clarity.
Of course, it's more than that. That end goal far from rules out the visual satisfaction factor, as when you think of it, a good spotlight should be visually pleasing. Looking professional is vital, in fact, to giving the subject the seriousness that it deserves. And looking "good", as vague as that may sound, grants the attention to the subject in the first place. Etc, etc. Everything that I just ruled out falls back into place. Except there's a difference—at least, I think—when you have this understanding on what is of ultimate importance. Subject over design. Purpose over exhibition of skill.
Easier said than done, of course. Yet I do find the nature of that challenge, with such a specific, concrete goal—despite the vastly creative sea of possible answers—to be an enjoyable and rewarding process. Teamwork is made especially fruitful, with everyone having more or less the same goals in mind.
I enjoy working on various aspects of graphic design—including but not limited to posters, booklets, books, t-shirts, websites, and really, any other challenge that may arise. I tend to sketch out analogue, brainstorming thumbnails with good old pen and paper, then moving on to Adobe Suite (Photoshop, InDesign and Illustrator) to adjust them according to the more clean-cut visual language made possible with computer graphics, as well as the creative commons resources I have at hand.