As a musician I learned to break things down into their component parts.  As a writer I never had the same instinct.  That's probably for the best since, as a musician, I often became so enthralled by the shape of the gears and sprockets that I never put them back together.  Still, being able to practice a skill is a skill in itself.  That's part of the reason I chose to read about poetry.  Poets (generally) always seem concerned about the mechanics of language more than prose writers (generally).  In A Poetry Handbook Mary Oliver suggests something like practicing rudiments or scales.  The rudiments and scales of writing being, among other things:

Meter, syllable structure, feet, length

Sound, consonant varieties, vowels, alliteration, consonance, assonance

Imagery, metaphor, simile, personification, description, action


So I suppose the difficulty lies in balance.