1) Adjust precisely 2) Adjust to perfection 3) Edit slightly 4) Hone 5) Improve in small ways 6) Make just right 7) Make minor adjustments 8) Make minor changes to 9) Make minor improvements to 10) Tweak Found on https://www.crosswordclues.com/clue/fine-tune
to tune (a radio or television receiver) to produce the optimum reception for the desired station or channel by adjusting a control knob or bar. · tune (def. 16). · to make minor adjustments in so as to produce stability, improvement, or the precise results desired: to fine-tune the nation's economy. Found on https://www.infoplease.com/dictionary/fine-tune