Thoughts:

Checking out Gerald Klickstein's The Musician's Way blog, I stumbled upon an article about rhythmic precision. He talks about the common misuse of the metronome which makes playing music dull. His advice:

1. Vocalize and move with the rhythm
2. Toy with timing
3. Vary emphasis
4. Focus on the downbeat
For this last one, he suggests putting a metronome in the background on the downbeat only while you play a piece. Record your playing and then judge your rhythmic accuracy. I'll try this tomorrow.

Additionally, leafing through The Musician's Way, I realized that I neeed to perform some memory maintenance strategies (p. 91) for my pieces - so that I image ahead while playing (otherwise I will start to rely on muscle memory).