Fractal

Fractals are also known as TSD stacking. It is a good alternative to Imperial Cross setup, which moves the Tetris hole.

Fractal 1
Two or more T-Spin Doubles layered above one another in the following even shape.

Fractal 2
Fractal 2 is a similar idea to Fractal 1, however the shape is uneven. Notice that with F2, the hang must be on the correct side to avoid blocking the hole.

Two T-Spin Doubles
By changing the position of the overhang, you can change from an Imperial Cross to Two T-Spin doubles, also known as a Fractal. This is useful if the garbage column is directly below the Cross.