refine

refine - verb

improve or perfect by pruning or polishing
make more complex, intricate, or richer
treat or prepare so as to put in a usable condition
reduce to a fine, unmixed, or pure state; separate from extraneous matter or cleanse from impurities
attenuate or reduce in vigor, strength, or validity by polishing or purifying
make more precise or increase the discriminatory powers of

refine - thesaurus