I have Tabuu's pattern memorized for those who want help. Here's how to handle each attack set:
*First attack - jump to set yourself in a position for Air-Dodging if necessary.
*Second attack - if he hasn't recently used his Off Waves, then jump, because his two moves besides Rapid Chop (easily evaded) are best dodged with a starting air position. If he has, then don't trust that going near him will be safe, because he may use the Projection attack; however, his remaining possible attack (Pinpoint Explosion) shouldn't be too hard to evade.
*Third attack - stay near the center at all costs. When he teleports once then stops, take a look at his position; if he's above the platform at all rather than on the sides, he's about to use Bullet Rain, which is a pain to shake off, hence why I tell you to stay near the center. His other two attacks are telegraphed, so you'll know when jumping is safe.
*Fourth attack - it will be Off Waves for the first cycle (or half-cycle), or Eye Beams for the second one. Fortunately, both aren't too hard to dodge even if you don't position yourself with this in mind, so you shouldn't need my advice about this.
And for those doubting my pattern memorization, a little run of beating him thoroughly with 1.5 times downward gravity:
http://www.youtube.com/watch?v=35jk1hGmFes&fmt=18
Tabuu used:
*Exploding Teleport - 9 times
*Non-Exploding Teleport - 8 times, not counting the Teleport right before each of the Rapid Chops (one being a double, the other being a quadruple)
*Shark Blade (1) - 3 times
*Diving Slash (1) - 3 times
*Gold Trap (1) - 3 times
*Chain of Light (2) - twice
*Electrical Shield (2) - twice
*Rapid Chop (2) - twice
*Pinpoint Explosion (2) - twice
*Tabuu Projection (2) - twice
*Dragon Laser (3) - 5 times
*Bullet Rain (3) - twice
*Shuriken (3) - 3 times
*Off Waves (4) - 5 times
*Eye Lasers (4) - 5 times, died on the 5th usage