Tchaikovsky's Opus 39 is a great set of short pieces for early to late intermediate pianists. Tchaikovsky sub-titled this collection "24 easy pieces (à la Schumann)". Like his predecessor, Tchaikovsky had the innate ability to write for young people, as illustrated here with this set of charming and characteristic miniatures. This piece is very challenging given the constant staccato repetitions. It will help you develop a fine control of your wrist while keeping it active and relaxed.