Beyond Hanon exercises, does anyone know of any kind of preparatory exercise, like a warm-up, to make the fingers more agile? Naturally, I could find something on the internet jungle. But I’m looking for concrete advice from someone who’s satisfied and has actually gotten results.
Hi Orlando 
Great question!
I believe Hanon is the go-to resource for finger strength and dexterity. I know there are other similar finger exercises out there but I don’t have enough experience with them to give you a recommendation.
From a jazz standpoint, it could be a nice idea to find a transcription of an improvised solo that you really like and try to play along with the recording and emulate the phrasing, touch, feel, accents, and other nuances of the performance.
I’ve been doing something similar with this recording of “Autumn Leaves” by Michel Petrucianni:
I really like his 2nd improvisation chorus from around 0:55 to 1:28. You can see that written out in the following transcription, starting at the penultimate bar on the first page:
- Autumn Leaves - Michel Petrucianni.pdf (96.7 KB)
The transcription doesn’t include his accents (which is what I find most intriguing about his playing) and so I plan to add them to the transcription.
Anyhow, I think this kind of exercise is complimentary to Hanon-style drills, and so perhaps you can spend some time on Hanon and then also try to play along with a jazz solo as an alternate finger strengthening and agility exercise.
I can currently emulate Petrucianni’s solo at around 75% of the speed that he plays, so still lots of practice to be done!
Nonetheless, I find playing along with the record to be a great way to ‘warm up the fingers’ and play with more agility and fluidity.
I hope that helps!