I found this funny post on tumblr and thought it a good visual commentary on the danger of copying style trends to excess.
As design students I think it's important you look at a lot of design (past and present) to expand your visual language as well as making yourselves aware of stylistic tricks of the trade. Keep in mind that when style begins to replace concept your work devolves and becomes merely superficial and decorative rather than original and hopefully memorable. If the majority of work in your book is full of stylistic trends that have all been done before, how are you going to stand out from a good number of other designers designing with the same visual vernacular?
You should continually challenge yourselves to take visual inspiration to a new place or better yet, go against the grain and try something you've never done before. If you've solved a design problem with a specific aesthetic, don't allow that aesthetic to creep into subsequent work. Take risks and challenge yourselves to grow with each project assigned instead of relying on safe visual cliches.
Ira Glass of This American Life talks about his creative process in the video below. He talks about why we make things and how that process is connected to our passions and taste. I like his analysis about the gap that results when skills haven't caught up to vision/taste.