Heh, think about placement too.
As you all know, Sonic tends to be seen as having crappy priority. However, we get around it by manuevering around to the opponents' weaker sides, attacking when the opponent misses attacks, and grabbing alot.
- For Olimar, he doesn't have an exact 'blind spot', and the closest one I can think of is behind him when he's grounded.
Think of this- a common situation if someone is landing near Olimar:
[Person lands]
[Olimar uses D-smash, just to be lazy and attack both sides, in case the guy's behind him]
[Person rolls toward Olimar, now in front]
[Olimar buffers a grab and catches him]
It's a simple mindgame/approach-counter, but as simple as it is, it catches alot of people. So if you land behind him, be ready to spotdodge so you don't get knocked back.
- Watch Olimar's pikmin:
If he has a purple one, don't get too close, and see if you can bait a smash or a grab, since purples have the least range of all his pikmin, in exchange for the most power.
Blue ones have the longest grab range.
Yellow, has alot of priority, so you want to try to get those out of the way.
White is a problem if he latches it onto you, since it bites the most damage the quickest.
Red cannot be knocked of by Falcon Punch or Falcon Kick.
- If he does Pikmin latch on you, don't be stupid and try to break it off, especially not with a Falcon Kick. Some smart Olimar players do Pikmin latch to bait 'breaker' moves and grab you out of it. Just be prepared to counter a grab. Only get rid of pikmin if he has 2-3 on you (well, 2 is manageable, but if they're "useful" pikmin, kill them), or a white one.
- Know how to drop and stage spike. It can be a dropping B-air, or even a full hop (reverse) Falcon Punch. Olimars know how to get people off the edge, but if you make him feel safe and know his tether length, you can bait a tether and get a flashy kill.
Keep in mind that good Olimar players will try to save their double jumps and avoid having to tether.