Following the tutorial this will likely be the next achievement you earn. This achievement is unmissable.
You'll be taught how to do grabs like the tail and nose grab as well as the indy grab. These grabs help you score more points on your jumps. Combos are done when doing multiple types of grabs in quick succession in one jump. Performing combos is necessary for high scores and some achievements.
Perform 5 or more moves and you'll unlock:
The ShowOff achievement in iStunt 2 (WP) worth 7 pointsPerform five different stunts in a single combo.
Then there are various point combo achievements: