If you want results, make sure that there is where you start from. Yes, I am talking about the end result(s). So, yes, that means working backwards. The next important step is making sure that everyone involved in getting you there is also in on the end, from the beginning. Keep the focus on the end goal throughout the process and let it guide and inform every decision that leads you there.
Start writing a brief from the end (goal) and then work your way back round to it. For a creative, you will find that this kind of brief inspires their best work, and gets the results you need.
If you are reading a brief and the end result is not clear, make sure that you clarify it before starting the work. It will clear the way to assessing which stipulations within the brief may inhibit or potentially prevent you from ever helping your client get there. These can then be discussed early on in the process. What is critical, what is important, what is less important and what is irrelevant will all become clear. The openness and clarity of the process will strengthen the relationship and the trust between client and creative because you are both focussed on the same goal and neither is lost in the details.