Your instincts are good and quiet. You have to go looking for them.
What it looks like in a life
Neptune sits in a sign for about fourteen years, so the sign is generational. The sextile to your Mars is what makes it personal. You do physical things with unusual feel: sport, craft, cooking, instruments, bodies. You sense the mood of a room and adjust without announcing it. You work well toward something you can picture, so you tend to see the finished thing first and then move. Your anger has a soft landing. You can be direct without wounding, and people notice that about you before they notice anything else. None of this is dramatic. It shows up in the work you have put real hours into and almost nowhere else.
The gift
You can be kind and effective at the same time. Most people have to pick one. You take action on behalf of people who cannot act for themselves, and you do it without needing to be seen doing it. Competition does not poison you. You can lose and stay open, which keeps you in rooms that close to other people.
The friction
The door opens when you push it, and you often do not push. Nothing here creates urgency, so the imaginative work stays a hobby, the compassion stays private, and you drift toward whatever is easiest to say yes to. Your boundaries hold, but only when you remember you have them, and remembering is not automatic.
The esoteric layer
The sextile is a sixth of the circle, two times three, harmony that has to be worked for. Hellenistic astrology counted it a benefit between signs sharing polarity, weaker than the trine, and read Mars as the lesser malefic. Neptune has no place in that literature at all, since it was not found until 1846. Bailey's esoteric astrology treats the sextile as opportunity rather than gift, skill built in this life, and gives Neptune the work of dissolving the separate self. Under a sextile, that dissolving is offered to you. It is never imposed.
Where this goes
The houses involved say where the feel is already trained and where it has never been asked for. A full natal reading is where you find out what is sitting unused.
Related
See it in your own chart
Cast your chart free and read this placement next to everything else you carry.