As INFJ's we need both alone time and people time. As full of dichotomies as we are, which makes us so wonderfully complex, we are here to serve others and in so doing, to serve ourselves. I must have both in order to exercise my functions and to achieve balance, internal and external. I, myself, use both routine and somewhat mindless tasks when engaged in introspection. Specifically, I live on a little Arabian farm, where every morning I get up about 4:30 and feed & water about 25 horses, very much a routine task that I could do in my sleep. I have the place to myself, stars above, critters to feed me vibes (I believe we thrive on being surrounded by 'life', human or otherwise), fresh air & smells of springtime to fill my senses - all culminating in a usually magnificent sunrise. This set of mundane chores in this setting is not a distraction but an enhancement to my process. I have arranged my life to do this every day. I am thus ready for whatever the day may hit me with. Similarly, I work in the arts, with my hands, leaving my mind free to wander, only interrupted by visual stimuli and the occasional weirdo artist, all pleasant and stimulating, not distracting. I work with one or two other people who I have 'trained' to quite enjoy my mental "bouncing off the walls".
I have found that I use interaction with people, newly encountered or 'an old shoe of a friend', as an opportunity to "exercise" ALL my intuition and feeling skills, somewhat playing a game in my head of "how can I make your day the greatest you have had in a while?" It serves to nurture not only them AND me, but the relationship as well, paving the way for a future pleasant encounter should it be someone I'm likely to encounter again. If you provide people with what they need, they will almost always unknowingly reciprocate.