Actually, my style depends a lot on my character. However, my prime style seems to be defensive, waiting for the right opportunity. I also lean on combos, mostly for my Main. I sometimes go for an in your face strat to lure the opponents, and depend heavily on my shield.
Mario (Main): Whem I'm Mario, his approach is not that good, so I always fight defensive, going offensive occasionally. I use shield wavedashes to approach. I always go for the deadly grab combos. I almost never use fireballs, and resort to D-Smash more than F-Smash. I pulse walk to fake out.
Pikachu: I go for an in your face mentality, also sticking to defensive tactics. I use thunderjolts to stun and lure the opponent to attack, afterwards wavedashing , shielding, running for them, or up-air. I am more offensive as Pikachu than Mario, abusing his speed, and going for combos. I go for SHFFL ANA and SHFFL AFA, and the occasional up-smash. I pulse walk to fakeout as well.
Samus: I missle spam, a ton. When in close range, I use the downsmash and forward smash to knock them away, so I can double missle. I also run for them sometimes, and use wavedashes to weave in and out. I really enjoy crouch cancelling.
Link: I take a similar approach as Samus, instead running in and shooting projectiles. I am more offensive with Link than Mario, Pikachu, and Samus, really enjoying the SHFFL forward air. I go for bomb combos, and grab combos as well. I am trying to get rid of my out of shield UP B habit [I also tend to jump in air as well], as it gets me in a load of trouble.
Fox: My worst character, I never put much time into him. When Fox, I am agressive, abusing jumping out of shines, and occasionally waveshining. I really enjoy pulse walking, and I suicide, too much. I can only control him when I am really on.