How to get really good on super smash bros brawl?

Practice in subspace emissary and then go to brawl.

I usually play as Toon Link because he is faster with just as powerful of a final smash as Link.

The trick is getting to know the characters moves and then learning what works and doesn't.

My favorite moves are Up B and his boomerang. The boomerang is great for working in farther distances and Up B can be used as an attack or a defense. Toon Link has okay bombs but I much prefer the boomerang.

Another thing to keep in mind when playing is what items you have selected. I turn off most like the Hammer and food.

If you use Toon Link I am guessing that you already know all this but I think the trick at getting good is to know the moves, know when to use final smash, and practice attacking in subspace emissary.

I hope this helps

Have Fun!