The Take-off line trick. If you manage to land on the take-off line in the Long Jump event, you can get jumps measured up to 500m, which gives a lot of points. In this recording the trick is shown on jump 2 and 3.
The Invincibility trick. You can get invincible by going down into the hidden Treasure room shown on the screenshot. This is of course not allowed as it takes away all need of skill, and just makes it a race against time.
The Pieces of Paper trick. There's a crate where you can get two papers. In that crate its possible to get unlimited papers if you carry a '?', and are searching constantly. This is not allowed. In the recording, the crate is reached when the Timer is at 418.