Glitch 1: walk under water
get turbo nozzle in the plaza.go to the fruit market.go behind the guy that "sells" mangos. turbo nozzle forward while touching the wall.ta-da! keep jumping or die.

Glitch 2:above the sun
go to episode 6 in gelato beach and get yoshi. do the dune bud glitch(spray and ground pound it just as it comes up) and get off yoshi. the only way to get out is to reset.

Glitch 3:Not fully on the ground:
go to the islands in the plaza with the slide down mini game.go to the island closest to the shore(the big one). dive down and you will see there is space between the rock and the ground!