This is an intriguing question, one I hope I might be able to shed some light on:
I am no good at starcraft, at least in comparison to those I play with, but I once was a grand master tetris player that played the world circuit for a time, and this is what I discovered:
Practice yields results. These results give you a rush, and you start to ascend, the more you play the better you play, the higher your score, or the better your results.
Now your opponents are more skilled, for they too have been going on the same cycle, and you find for every match you win, there is another you loose: 50 - 50 ratio.
This is where the gameplay gets interesting: if you want to advance you will have to realize some things.
Energy and time output. The further you want to advance the longer it will take, for example: going from the skills to achieve master tetris player rank to grandmaster in the world circuit was much more difficult than getting the skills to be of 'master' rank.
What I learned when I plateaued as an advanced player at an advanced rank was that, in order to continue, I needed to unlearn everything I knew about playing tetris and relearn how to play the game from the ground up using my experience in the execution of the game and going from there; this got me to master, and when I hit master I also plateaued, and in order to get to grandmaster, I had to completely relearn how to play the game for a third time, at this point i had retaught it to myself 4 different times, each succeeding time with more rules, theories, and how to best capitalize on luck.
This is why I say: Practice yields results. Practice does not make perfect; perfect practice (I.E. that thing you learn once you reteach the art of play to yourself for the umpteeinth time) makes perfect.
If you have plateaued, I would recommend taking everything you have learned about the game up to now, archiving it for reference, but focus on coming at the game with a new perspective. A friend of mine plays MLG fps's and destroys everyone he plays against outside of upper competitive gameplay, and he can't aim. His aim is absolutely abysmal, but he makes up for it by knowing how fast his character moves in each of the maps, he has researched the button magnetism per game, he knows the distance from one place to another and calculates the resulting probabilities of death and luck; but generally he relies on plain trickery, solid reflexes and many hours of gameplay.
I am no good at starcraft, at least in comparison to those I play with, but I once was a grand master tetris player that played the world circuit for a time, and this is what I discovered:
Practice yields results. These results give you a rush, and you start to ascend, the more you play the better you play, the higher your score, or the better your results.
Now your opponents are more skilled, for they too have been going on the same cycle, and you find for every match you win, there is another you loose: 50 - 50 ratio.
This is where the gameplay gets interesting: if you want to advance you will have to realize some things.
Energy and time output. The further you want to advance the longer it will take, for example: going from the skills to achieve master tetris player rank to grandmaster in the world circuit was much more difficult than getting the skills to be of 'master' rank.
What I learned when I plateaued as an advanced player at an advanced rank was that, in order to continue, I needed to unlearn everything I knew about playing tetris and relearn how to play the game from the ground up using my experience in the execution of the game and going from there; this got me to master, and when I hit master I also plateaued, and in order to get to grandmaster, I had to completely relearn how to play the game for a third time, at this point i had retaught it to myself 4 different times, each succeeding time with more rules, theories, and how to best capitalize on luck.
This is why I say: Practice yields results. Practice does not make perfect; perfect practice (I.E. that thing you learn once you reteach the art of play to yourself for the umpteeinth time) makes perfect.
If you have plateaued, I would recommend taking everything you have learned about the game up to now, archiving it for reference, but focus on coming at the game with a new perspective. A friend of mine plays MLG fps's and destroys everyone he plays against outside of upper competitive gameplay, and he can't aim. His aim is absolutely abysmal, but he makes up for it by knowing how fast his character moves in each of the maps, he has researched the button magnetism per game, he knows the distance from one place to another and calculates the resulting probabilities of death and luck; but generally he relies on plain trickery, solid reflexes and many hours of gameplay.