This is a YouTube playlist of difficult/important strats. Note that not all stages are included, and some stages have multiple videos (usually showing different strat options). If you want to learn how to speedrun Super Monkey Ball Gaiden, it may be helpful to follow along with a few runs on the leaderboard while also checking this playlist.

https://youtube.com/playlist?list=PLG1btiUORGnNouB_h1id0d8qLP9T6TAaw