well don't do the mistake as many people do, think that spamming f & dsmashes also his blaster is the top notch way to win, if you meet someone that's at least a decent good player he'll just shieldgrab you. Short hop fair is a very good move when your opponent got a fairly high % and ofcourse levaes himself open, after that when you got him in the air the 2 attacks I use most is then fair and bair, but as you play some matches it might get predictable, so mix it up with other attacks and sometimes jump up after him but don't don anything just to confuse him, and maybe land a dsmash after you hit the ground.
Where do you live? if you live somewhere near sweden we can take some matches if you want ;D