EnigmaticScarecrow
Smash Cadet
If you're not already, maybe you could try practicing more seriously with your character. For example, if you main Sheik (whom I'd recommend due to her easy learning curve), you won't just be able to perfectly reaction tech chase instantly, and will have to grind it until you can do it consistently.
The reason I say this is because when I'm just playing for fun, I go plenty of different characters as well, but usually stick to Marth during a practice session. I'm pretty sure the grinding helps because it gives you more to focus on for longer periods of time.
I'm not saying you have to give up playing multiple characters in friendlies, but if you have one character (again, I'd recommend Sheik) that's your best, then that might help you find a main.
The reason I say this is because when I'm just playing for fun, I go plenty of different characters as well, but usually stick to Marth during a practice session. I'm pretty sure the grinding helps because it gives you more to focus on for longer periods of time.
I'm not saying you have to give up playing multiple characters in friendlies, but if you have one character (again, I'd recommend Sheik) that's your best, then that might help you find a main.