Gymkhana Skip is essential for Season 1 as it lets you skip a pretty significant chunk of the gymkhana tutorial missions (spin, smash etc.). It's about as simple a skip as they come. To do it successfully, you need to earn a bronze medal in the gymkhana tutorial missions, and then retire through the in game menu. This will quit the event, and the game will see you as having earned a bronze medal. Trying this in the actual event as the season ender won't work, and will give you a DNF instead. This skip is currently banned in NMG, and using it there will likely have your run moved to standard season 1.

Here is tSu_nAmi performing the skip: