Most fighting stances are too exposed. They are either facing to the front so you may fire with both guns or they are tucked away where it is difficult to use rear hand or leg techniques. When you give too much front exposure, the trade-off for being able to throw more angles is that you are more open to being hit. On the other hand, when you are too closed off, it is just a short step for your opponent to get around the outside of your lead foot, leaving you exposed. The solution is a compromise. Draw a line from your rear heel through your lead big toe to the opponent's centerline (as in a back stance). Now you are in a position where with a small adjustment you may open up and fire away, or, with a small adjustment, you may close up.
Concentrate on few kicks
There are countless kicks and combinations in Taekwondo but you only need few of them to be successful in tournaments, such as the basic front, side, round house, hook, and axe kicks. They are simple and more effective and efficient than other more "aesthetic" kicks, such as butterfly, tornado, 540 side, etc. The most frequently used kicks are the roundhouse (most used), back, and axe. Side kicks are used mostly by traditional fighters, but successful competitors may effectively counter these kicks. Kicks to the torso score points more frequently than kicks to the head score. Spin kicks are the least likely to score.
Do not get into foot fight with an opponent. A foot fight is similar to a sword fight where swords are swinging around banging into each other with no injury to either fighter. In a foot fight, both fighters are trading kicks, wasting energy, and getting nowhere. Only kick when you see an opening, not in response to an opponent's kick.