As this ad for Mercedes shows, the left brain is in charge of logic while the right comes up with all the creative stuff.  But many people get stuck while trying to tap into their creative side, mainly because it has little form to it and is often approached from the wrong perspective.

lr.JPG
Image via Creative Criminals

One good example is writing. During the beginning phases of great idea, an editor must balance between being creative, making sure they don't produce anything bad and remembering to consider the marketability of the topic. While having these different perspectives to view your creative work is great, you need to keep them in check to avoid sabotaging your productivity.

Tara Mohr of The 99 Percent explains a little more on this:
In the early stage of the creative process, we need the inner artist. The artist's domain is drafting, receiving ideas and inspiration, fleshing them out. The artist thrives in an atmosphere of curiosity, safety, and play. She needs shelter from others' opinions and respite from even thinking about what the judgments of others might be. In the second stage of the creative process, the inner editor leads. The editor's domain is revising, trimming, structuring. Whereas the artist must forget about what other people might think, the editor brings the audience back into the process, ensuring that the work effectively communicates the artist's intent. Then the inner agent takes the baton. The agent's domain is developing marketing messages for the work, communicating about the work to external stakeholders, and finding distribution. The agent is thick-skinned, brave, and wise about the market.
Be advised that this not always a linear process, so you'll have to switch it up depending on the circumstances. But the most important thing to keep in mind is truly knowing your own creative self and process.  For more suggestions on how to unleash your fullest creative potential, check out the full post on The 99 Percent.