深耕细作

• 氵(water; liquid)RADICAL
• 罙(deep into cave; enter cave depths)PHONETIC

Water flowing into a deep cave evokes the meaning of profundity.

• 糹(thread; fiber)RADICAL
• 田(field; paddy field)PHONETIC

A thin thread like a furrow in a field is small and delicate.

• 亻(person; people)RADICAL
• 乍(sudden; just beginning)PHONO-SEMANTIC

A person beginning to do something is the action of making or creating.