It's not the planning, it's usually the "hanging in there" that makes the difference between success and failure. Most plans represent good ideas, laudable goals -- isn't that why you came up with them? So, why do many plans fail outright or fail to achieve the goals they were intended to achieve? For the answer, look into the mirror. In almost 30 years in consulting, I have seen more plans fail due to lack of perseverance than for any other reason. "Hanging in there" just gets too "old," or "too difficult", or just "wasn't what I expected".

Are there ways to make plans and planning efforts, more successful? Several come to mind, but the most important (to my mind) are:
Start Small -- your overall goals may be lofty, but the daily goals along the way should be like steps on a staircase. Each step needs to be big enough for your feet and high enough to raise you to a new level, but also small enough for who you are, and where you are, at that particular time. When the goal is too high, or too far, it is too easily seen as too tough.
Active Audiences -- the more you share your plans and their goals with others, the more likely you are to achieve them. After all, if you only tell yourself and don't follow through, who's the wiser? When you tell someone else that you are going to do something, there is a magical push that comes with their knowing. And, you get cheerleaders, constructive (and un-constructive) critics, and reality checks along the way.
Reward Results -- celebrate each small victory and gift to yourself for memorable achievements. All too often we punish ourselves for any failure, but don't reward our successes. The celebration may only be an emphatic "YES!", but the recognition is important.
Balance Behavior - it is said that life is all about learning, earning, and giving back. A balanced existence gives us time to recharge our internal batteries and gain strength for tomorrow's challenges. Work-aholism, like most distortions, is not good for you.

Thought To Action -- Start small, and take it from there. What is it the Chinese say about every journey beginning with a single step? Step lively.