Most people make the mistake of thinking what their next step is going to be on the "road to success." The problem, of course, is that they haven't given anywhere near sufficient thought to what actually constitutes success - at least for them. So while they might look at Don Trump and say, "Aha! What I need to do is buy a bunch of real estate," they haven't first determined that what they're interested in having is a large real estate portfolio that generates passive income and an enormous ego. Now, those may well be desirable ends for some folks, and thus following Trump's route may be a successful way of getting there. The problem is that after a lifetime of pursuing this route, some people, maybe even including Trump, realize that actually that's not what they were looking for. Maybe they get to the end and find that instead they wanted intellectual distinction or the experiences that come from world travel. Fine.
So clearly the key here is to start with the end game and then back in to what it takes to reach ultimate success. I made the same mistake when I attended business school. I went to business school because this is ostensibly a good thing to do. And it is. If you do it for the right reason. Business school is a fancy trade school, no different than studying law or medicine. If you want to be a doctor, clearly there's no better answer than med school, but the converse is also true. Med school makes exactly zero sense unless you want to be a physician.
When you attend business school, you'd best first understand what it is that an MBA can do for you. This is not the place to discover what business could mean to you. You don't have nearly the time, and the entire program is structured against you. It's designed for people that already know their end goal and understand that this is a two-year interregnum and/or stepping stone that gets you there. Period. Writ large, there's no reason that anything else in your life should be any different. Figure out where you want to be at the end. Determine the steps necessary to get there. Derive metrics that provide you with along-the-way feedback on whether or not you're following the appropriate path. Then measure your daily activity versus these metrics and adjust accordingly.
There are a number of basic guiding principles that can help with this process, but nothing will be more beneficial than the simple process of questioning each day's activities and lessons, fully realizing that there may be small detours along the way. But success is ever so often the product of rigorous application rather than innate talent or luck. The truly successful are more likely to incorporate all three of the above, but a conscious effort to unify them is more than likely to lead to success.