Here are some tips:
Goomba wrangler: Draw circles as fast as you can, it actually doesn't matter if you miss a golden goomba, as long as you don't circle any bombs.
Camera shy: Either follow one enemy so you can take a photo of 2 of them or run in a circle and take photos, both are effective.
Study fall: You don't always have to go for 000.0 inches, sometimes a close enough is enough to win.
Trace cadets: Treat your stylus like a pencil, that's it really.
Hanger management: Stay in the middle as much as possible and only lean left or right at the last possible moment.
Hedge honcho: The bees and ladybugs will always hide behind a vertical leaf, a diagonal leaf
will always show part of it.
Hot shots: Sometimes it doesn't matter if you miss a bowser, combos give more points
anyways, focus on hitting your targets consecutively.
Boogie beam: Pretty much an easy reflex game, the last one is a guaranteed spotlight on everyone.
Parachutin' gallery: Pretty straightforward, you can also push your opponents away from a correct one to ensure your victory a lot easier.
All geared up: Follow the exact steps I do and you'll always get the top the fastest.