What has worked best for me as Fi at work to be quietly kind and polite and then whenever possible show kindness through action. Like at work, try to be the patient one who is willing to take a moment to help and to ask when I have time if I can help others. To be kind and patient when things are stressful and going wrong. Be known as the person who is easy to deal with. That's the best way for me to develop valuable friendships at work. Also to be a listener, someone who is willing to truly listen and understand. There's always some aspect of a person that one can feel sympathy for it seems.