Drill down on what you are trying to find out. Whether it is for you or for someone else, before you start your research, ask what decision you (or someone else) can make or action you (or they) can take once you are done. If you cannot answer that, step back and rework the assignment. That way you avoid wasting time in the “nice to know” swamp rather than staying on the “need to know” highway.
Scope out where you will probably be looking before you start looking. Divide the potential sources – and leads to other sources – into primary and secondary. Start with and plan to finish the first round of secondary before starting the primary. Save the primary for when you have “mastered” the issue, so your interviews will be short and to the point. You can avoid wasting a valuable, hard to schedule, interview getting what you could have collected from reading.
Again, before you start, write down your key question, the core of your assignment. Then, list the 3 or 4 questions you must answer to get to the core question. If necessary, break down the sub-questions one more time. You now have your research outline. Think it through. How likely is it that you can conduct the research and produce the necessary analysis – under your time and cost constraints? Put a number on it. You and I know it is only a rough estimate, but you are already calling on your subconscious (or your gut, your call) to help on your project. Look at the numbers you assigned: why is it the third question has only a 25% likelihood of success, while the fifth question is at a 90% likelihood? How you can restate the third question to make it more likely to succeed in answering it?
In other words, don’t start until you have it clear in your mind where you are likely to go – even if you do not always know where that is.