Earthbending training

When Toph train Aang in Eartbending in the chapter Bitter Work, she uses a number of different types of exercises. These are the various Earthbending trainings that Toph uses:

Stone carry maze run
In this exercise, Aang carries a heavy stone on his shoulders while running through an obstacle course. This exercise is designed to keep Aang grounded and train him to use the earth for balance.

Sand punching
In this exercise Aang punches into barrels filled with sand. This is supposed help Aang get a better "feel" for the Earth but it can also be very painful if you do not use proper Earthbending.

Whack-a-rock
The "whack-a-rock" exercise is like our version of the "whack-a-mole" game. Toph Earthbends rocks, quickly popping them up and then back into the ground at the same time, Aang tries to whack them.

Rock armor
In this training technique Toph covers herself in "Rock armor." While in rock armor, Toph acts as a live sparring dummy for Aang.

Sand sack throw
In this training exercise, Aang takes a stance and throws a sack of rocks from behind him up in the air, then moves forward and catches it.

These exercises are all designed to help Aang in different areas of Earthbending but in general, they are all used to make him more "rock-like."