These are designed to cover a certain aspect of piano technique. Some are short exercises and some are full pieces.

Articulation

Right hand legato, left hand staccato in C major
Right hand legato, left hand staccato in G major

Octaves

Octave shifts in 5-finger patterns (2nds)
Octave shifts in 5 finger patterns (3rds)
Consecutive octaves

Rhythm

Stepping Out - a short piece with syncopated rhythms