After a lot of study and experience, my approach these days, in order, is 1) Put complete trust and rest in God through Christ (the “Great Physician” Himself, not faith healers), 2) Get proper nutrition (I recommend Prescription for Nutritional Healing, by Phyllis A. Balch, 4th, ed.), and 3) Exercise.

Following the above may not preclude use of pharmaceuticals, but may greatly reduce dependence on them in the general case, and is often much more effective for the long term.

Of course, prevention is much easier than cures, when possible.