ESS Position is the smallest input the game can register that makes Link move. When holding ESS, Link will turn around and shuffle his feet on the spot, unless you started holding ESS while targeting. An interesting and extremely useful effect of ESS Position is that it allows us to maintain speed.
A FESS is the fastest form of ESS Sliding in MM3D. A FESS can easily be performed by holding ESS, taking damage from an explosive (usually bombs) and pressing L right after.
Due to the changed rolling in MM3D, an ESS with the speed of a HESS is impossible. You can get a backwards ESS, however the speed is actually slower than a FESS.
Using ESS position, it is possible to dupe bottles over items and masks. For more detailed information, check the Bottle Duplication page.