When you are engaged in creative work, it is important to keep a close eye on what you are consuming. You tend to be severely influenced by what is feeding you. You will also tend to imitate the people that you hang around.
With this in mind, I started a project some time ago. On any day that I had time, I would start my musical day by meditating on a Bach Chorale. I sang through each of the parts. I made a quick Roman Numeral analysis. I made note of interesting voice leading and spacing.
Today, I finally finished #371 in the Remienschneider book. Here are a few conclusions after looking in detail at every chorale that Bach harmonized.
Robert Helps used to do a composition excercise with me that he used to do with Roger Sessions. Take a chorale. Harmonize it. Compare it to what Bach did. See how much you suck. Bob would say, "Whatever you do, you'll probably find that Bach was more adventurous than you." That's still true.
More than anything, I've also found that I tended to move into distant areas before properly establishing my home. The chorales are like concentrated lessons on how musical motion works. They teach the balance between unity and diversity, motion and stasis, and above all, how far you can stretch something without breaking it.
I also think it's a good project for any musician to do. It has given me hours of pleasure in aesthetic contemplation. I also now know which one is the best one, but I can't tell you. You'll have to go through them yourself.