I want to preface this with the fact that I think EVERYONE should go out and buy the MGMAT Advanced Quant book. It's great on a lot of levels. Some of the concepts that I mention here are covered in the book and some in more detail. I try to present a broader framework here.
When I first started studying I combed over posts in the experience section as if they were case studies. I looked for people who succeeded and tried to model my study practice after theirs. I always wanted to know the sources of their problems, how much time they spent on each section, etc. While this isn't a bad practice in general (heck it's the whole basis for what Tony Robbins teaches), what I am here to tell you is DON'T DO THAT. Do something much simpler: be agile.
The strategy framework I used for scheduling my time is something you will see in everything from problem solving to lean process:
- Understand
Plan
Execute
Analyze
Most people tend to do the middle two, and usually it goes something like "copy a plan of someone who scored well and do the same problems that they did." Again, what I am saying is DON'T DO THAT. Everyone is different. You not only need to understand what you need to do to get to your goal state, but also need to periodically analyze if what you are doing is working. Skipping the first and last steps would be like asking the question "how do I get to Chicago?" and then getting an answer like "drive 2 and a half hours south." That works if your starting point is here in Madison but not anywhere else. Not analyzing would be like not looking at the road signs and the clock to determine if you are going to make it to your destination on time. It's POSSIBLE to work without doing these things but not OPTIMAL.
So what does this mean in terms of your planning?
Don't create a grandiose initial schedule. For those of you familiar with Scrum you'll note that this is similar. You have 2 week "sprints" in which your workload and prioritization are fixed. During this time you simply "play". At the end of the two week sprint you look back at what you did, pick an improved, intermediate goal state and then decide what you want to try in order to get there. You are flexible and near sighted. It is true you do have an overall goal in mind (usually something like "score a 730" or some such) but there is NO WAY anyone can say what specific steps are needed to get from their current state to the goal state in a complex game such as this.
Get an initial score before you start studying. Read an overall description of the GMAT, such as the one in the OG, and then take a practice test. If you don't do this there is no way you can understand the problem that you have and thus no way you can move into the first plan phase. It doesn't have to be a GMAT prep (some advocate saving authentic problems for close to the exam which is fine) but it has to be something that will give you an idea of your current state (Kaplan's test was fairly accurate for me).
Don't schedule your exam until you have some idea where your velocity intersects with your goal state. That is to say based on how fast you are currently increasing your score, when will you be where you want to be? You can only determine that after you start studying and tracking your progress.
When taken this way planning and studying for the GMAT (and really the GMAT itself) is actually quite simple. It boils down to using the above process to iterate over study sprints and learn from your mistakes.
But while it is simple, it's not easy! You'll have to put in a bit of time and quite a bit of critical thinking. And you'll fail. A lot. And you'll struggle to overcome those failures. However at some point this process will allow you will learn to stop thinking about success and failure and to simply acknowledge each event as a lesson learned. After that your ideal score is simply a function of time.