I think being a strong player has 3 components:

1. Knowing how to move your tori. A good understanding how to turn around, land on your feet and pack a punch are very valuable.
How to practice: Play mostly Lenshu and Sparring and try to keep your feet mostly grounded. Also play single player and study how the joints of your torso affect your movement.

2. Knowing how to dismember. There are a few tweaks you should know that really push the effectiveness of your strikes right before they land.
How to practice: Play taekkyon online or play single player and create some "madman" replays (replays in which you try to dismember Uke as brutally as possible). It can also help to study replays from the book of records, since they do it better than anyone else.

3. Understand a mods meta. Every mod has some common openers and situational maneuvers against which you need to know some counterplay.
How to practice: Don't minimize toribash when it is not your turn. Watch other players. This is especially true when some guy has a 10+ win streak. Most likely this person uses the same tricks over and over. Think about the weaknesses of their actions. Are they unbalanced on the ground? Is their attack actually easy to dodge but everyone loses because they just contest it? Also it helps a lot to just talk and play with strong players.