With this simple trick, you can earn at LEAST 100 Red Star Rings an hour.
What I use:
SPEED AND FLY TYPE STAGES
Halloween Rouge & Vector
Red Star Ring Battlecruiser & Black Knight
Equip a laser and run through like normal. Once at the first Eggman, switch to vector and keep tapping the screen while accurately avoiding springs. This will cause Vector to charge multiple times which in turn causes you to reach Eggman faster, thus giving you more chances to get more red rings.
After the first segment is complete, use your laser to skip over most of section 2. Then do the same thing with the next Eggman. After that, you should have easily collected at the very least 5 red rings (hopefully more than that) and you can go ahead and kill off your characters.
POWER TYPE STAGE
Halloween Omega & Omega
King Boom Boo & Boo
Just get 10,000,000 pts as fast as you can for an easy pick up of 5 red rings for completing the episode.
I hope this helps you guys out. I'm able to successfully obtain 100 red rings on the hour easily, sometimes more with this method.