Herbert Clarke's practice regimen (in case you're looking for a crazy hard New Year's resolution)

[A]t my father's suggestion I took up the study of the viola. He said that if I could learn to play it well enough we would form a family string quartet . . . .

I immediately planned out a schedule for myself to play four full hours on the cornet each forenoon, with four on the viola every afternoon. . . .

One never-to-be-forgotten Sunday afternoon, about a month from the time when the project originally was started, we made our first full try-out on one of Mozart's beautiful string-quartet compositions. Everybody became so deeply absorbed, and the time passed so pleasantly, that nobody gave any thought about supper, although we were called several times. Father suddenly remembering that he was supposed to play the organ at evening church service, finally jumped up and left precipitately without stopping to eat. The rest of us then came down to earth long enough to eat.

This experience, new to me, was so fascinating and so increased my love for good music that I became more determined to follow out my previously planned schedule for routine work and study in a systematic manner. In detail my schedule was as follows: The cornet in the forenoon, with one hour on scales, one hour on slurring, one hour on tonguing and one hour on miscellaneous work: i.e., a little of each of the preceding combined with playing songs and easy solos. I kept this up all that winter, getting up early and working from eight in the morning to twelve noon. The afternoon was devoted to the viola, carrying out the same general system in scale playing, finger exercises, bowing, and playing parting from the different string quartets. My improvement on both instruments astonished even myself.

Herbert L. Clarke, How I Became a Cornetist: The Autobiography of a Cornet-Playing Pilgrim's Progress (1934), ch. 12. (He was 17.)