Try not to spam the button to navigate the menu quicker, only when the "Press A or - to Skip" buttons actually appear, it will save seconds at most.

Try to get an OK on every game, the medal animation wastes seconds of time and can cause the "Go For a Perfect!" box to show, which also wastes time. The standard for getting an OK is missing 5 - 8 times at the start. Except for very long games, like Flock Step or Tambourine.