The success in taekwondo would be in reach if the trainee respects a few rules and train correctly, not everyone attending taekwondo classes would be good at it or master its techniques, there are many mistakes that students commit without even paying attention or without knowing them.
Here are few tips of what you should do:
Train regularly three or four times per week
Most people do not put Taekwondo as a priority in their weekly plan, and they complain about their busy life and other commitments.
Practicing taekwondo once a week is not enough to learn taekwondo techniques, or or increase your stamina.
The student should make taekwondo as a priority in the week plan and has to train regularly.
Do not practice your favorite techniques only
Having favorite techniques is a normal thing for every taekwondo practitioner, but the wrong thing is to keep practicing your favorite techniques and forget about others. The practice of a kick or any technique is the key of learning and mastering them, that is why the students should train all techniques in their training program.
Concentration
The student should be 100% mentally focused during the training in order to have a good control and precision while practicing techniques.
Avoid training excessively
The trainee should not cross the limits during the training and has to avoid getting too tired, because this could lead to a serious injuries.
Focus on mastering basics of taekwondo
Some students try to learn advanced techniques while they are still struggling with basic techniques.
Sometimes new students get impressed when they see black belt holders performing some beautiful kicks or do some superior poomsaes (forms), and they try to learn those advanced techniques because practicing the basic techniques seems to be boring for them!
Taekwondo students have to spend time practicing the basics in order to master them. Ignoring the fundamental techniques of taekwondo would make you end up as a bad black belt.
Breathing
The trainee should relax during the training, and has to breathe deeply when kicking or punching. Weak breathing means insufficient oxygen intake which may cause dizziness and low energy.
Go early to your training
Going too late to taekwondo training means missing the warm up and stretching part, and this would affect the whole training session, because it is a fundamental part in the taekwondo training.
Train both sides the same way (right and left)
In most dojangs, it is noticeable that some students can use their right side better than the left one or the opposite, and this is a result of the imbalanced training. The student should train the weakest side much more to improve it.
I hope these few tips would help you to progress in your training.
Good Luck