If in Hard Mode mode or Insane mode, if your having a hard time seeing the notes. Flip DS upside down and play it like that. The notes are easier to read, and a little bit slower.
Your score will be much higher if you play without the timing rings.
Markers are worth 1.5 times more points, meaning that a 50 will be 75, 100 will be 150, and 300 will be 450.
This will make your score for a stage much higher than playing with the timing rings even if you got all 300s with the timing rings.