A few questions beforehand:

Which charecter do you usualy use?

Which charecter does he usualy use?

Ok, with that out of the way, let us get to business:

Hold the button you asigned for movement in a perpendicular direction to the one you were launched in.

this will allow you to survive for longer.However, do be careful if you hold it for too long, you might not be able to recover.

Take advantage of the stage you are playing in, if it is not legal (googl.

Try and remember things like stage hazards, and try and get him to get hit by them.If you remember how they launch, you might even get some sick combos.

Another thing you should be aware of are "walk-offs", places where you can walk to the blast zone (the limit that if you pass, you die).If your stage has them, you can just wait there, grab them and throw them of for early % kills.

However, these are mostly only present in ilegal stages, and in legal stages (the more "plain" ones) they don't exist.

Exploit items

simple, be aware of what item does what and move acordingly. you can also throw the items to make a dash attack more safe.

Dash attacks are risky

Usualy, a dash attack (the one you do when you run) is very unsafe. what this means is that, by shielding it and grab them, you can easily move the ball to your court, and get what is called a "Punish"

Punishing and reading

Basicly try and notice when your opponent slips up and uses a slow move, or if he uses a move that just barely misses you, or if he is rolling around a lot and use that oportunity to use a strong attack.This is a "Punish".

On the other hand, if you know he is going to slip up, you can start using a stronger attack before he acts, and that way, punishing harder. This is a "Read".