I’m not good at teaching but hopefully this helps you

Video link:

NOTE: Shroomless only worked with peach and bowser

Shroomed: 1. Go to the last yellow ramp, back up and aim where the left walk and ramp meet and Shroom

SHROOMLESS: 1. Start a turn to the left when you are about to hit the second last ramp.

2. Continue your turn/drift when you get to the last boost panel and you should make the cut.