Usage patterns
〈人〉一人一人に声をかけるto speak to each person individually
The teacher spoke to each of the students individually.
一人一人の個性を大切にするto value each person's individuality
This school values each student's individuality.
一人一人が〈動詞〉each person (does something)
Each person presented their own opinion.
一人一人に合わせて〈動詞〉to do something tailored to each person
The teacher changes her teaching style to suit each student.