[いってんいっかくもおろそかにしない, itten'ikkakumoorosokanishinai](exp) always dot the i's and cross the t's; don't neglect the slightest detail; be punctilious[Add to Longdo]
[しゃかにせっぽう, shakaniseppou](exp) teaching your grandmother to suck eggs; teaching something to someone who knows more than you; lecturing to the Buddha[Add to Longdo]