How do I choose the BEST concept for this print ad project?

So you've explored all sorts of great ideas for your brand and you have found great supporting imagery, photos, illustrations, and type. So how do you choose the best solution to move into refinement and execution?

1. Consider how well the collage art aspect of the design is? If you have a cool idea but the collage art aspect of the project is lacking, perhaps you should go with a different idea that has a stronger aesthetic look and feel. 
2. Consider the message you are communicating. Is it clear? Does the message convey to your target audience? Does it make sense for your brand?
3. Re-read the project brief in case you forgot any details required for the assignment. Read it for the first time if you haven't read it at all! Make sure you are implementing found imagery, an existing logo, and an existing tagline. 

Your concept should be successful if all these elements are addressed!  After you have chosen your concept, make sure your 3 ads have a general synergy across design elements?