ISFP People of this type tend to be: kind, humble, and highly empathetic; thoughtful, faithful, and affectionate with those they know well; sensitive to criticism and easily hurt; quiet, soft-spoken, and gentle; adaptable, responsive, and curious; realistic and down to earth. The most important thing to ISFPs is feeling peaceful and harmonious with the people and places that matter most to them.
How to Spot ISFPs: gentle, soft-spoken, and modest
relaxed, easygoing, and accommodating
unassuming and not terribly assertive
fun loving, caring, and sensitive
Tips for Communicating with ISFPs: Avoid confrontations! Be cooperative and gentle
Stress the practical ways they can be of assistance to others
Make projects fun - enjoy the moment with them
(From PersonalityType.com)