heighten, raise, improve, augment, enrich, strengthen, maximize, increase, optimize, bolster, more...

diminish, reduce, weaken, impair, degrade

intensify, brighten, deepen, lighten, saturate, more...

to improve,   improve, in a way,   make effective,   add value to,   greatly improve,   make more effective,   make more beautiful,   improve performance,   improve skills,   improve quality