I like the last one also. I'm usually working on around 5 pieces, so practice time dedicated to just technique tends to fall through the cracks.
I got curious recently about what technical practice & challenges I might be getting from the pieces I'm working on or recently worked. As an example:
Fast Tempo - Burgmuller Limpid Stream
Finger/Hand Independence - Beethoven Ecossaise
Jumps - Manhattan 1928 - Nancy Faber (Piano Adventures)
Large Chords - Beyond the Sea
Rhythm - Beyond the Sea
Based on the area I feel most challenged in the pieces, I could choose future pieces to target those skills.