Hello! :-)

Do you have any good suggestion on mindfulness audio-books which I can listen to when walking in the city and sitting on the subway? 
I would like to extend my practice to those areas as well.

All the best

What kind of meditation do you do? Do you do metta? If so, maybe just smile, relax, visualize your spiritual friend, and wish them well. Feel the wish that they be well. This is what I do on my daily walks. If you know you're feeling the wish, that's fine. If the feeling fades, you might subvocalize again to make another wish for their well being to help bring the feeling back up.

I want to practice metta thank you

Do you practice metta in your sitting practice? Do you need general instructions about how to do it?

It sounds like "The Inner Art of Meditation" by Jack Kornfield is someting like what you are looking for.

But that is not what I do. My suggestion is to breathe in a relaxing way, relax as you exhale, relax as you inhale, notice the pleasant feeling of relaxation as you inhale and exhale. If you feel tense, try to relax the tension. Notice what makes you tense and what helps you to relax. You can do this sitting, walking, washing the dishes etc. In addition to meditation, explore different types of relaxation exercises.

My view is that dukka = stress. Understanding the origination and cessation of dukkah/stress (the 2nd & 3rd noble truths) is what leads to reduced suffering.

"If you could be relaxed in every situation, what would that be like?" You could take this as a koan, it might be helpful.

Hi - I practice metta-meditation when I am sitting. I have been meditating with the Mahasi-Vipassana method but I realized that this is a very object based type of meditation and I did feel somehow it forget how to interact with love in the world with other humans. I just discovered Jack Kornfield and followed some of this Mindfulness instructions and I really like it because it feels more "human" than the strict Mahasi Vipassana. I dont know how to say it in another way. What I am looking for is suggestion on how to in my daily life when i am walking around in the city, or teaching in the classrom how to be more compassionate, kind and how to reduce anxiety when it arises in human relations

Thank you