I'm not acutely aware of Ni. I can never quite "decide" or "consciously realise" that I'm using it. It's there in the background, unconsciously collecting and synthesizing information, until later I realise that I reached a synthesis without deliberately trying to do so. It's not really my thinking that's convergent (it also is, but in a more deliberate way that can also be achieved by Ne and Ti), but my intuiting, "prior" to thinking itself in a way.
So I'm more aware of Ni "in retrospect", or by deduction. Sometimes I experience this as actually bothersome, like I wish I had a more expansive perspective instead of some kind of tunnel vision on things. It's very patent when I'm at work brainstorming with ENFPs and their combination of Ne and Te - I really feel like I operate in exactly the inverse way. But in the end we work well in tandem because I can extract the essence of their thought process and help them select the best ideas/course of action.
Another way I'm aware of Ni "by deduction" is when I can tell my mind has just done something "that sounds like Ni" as per what I've read on the internet. That involves the symbolic abstract ideation (which I can be quite conscious of, as it's the direct inspiration of my own creative writing), the lonely eureka moments, the ability - when I'm well-rested - to sort of track my reasoning as I'm thinking or talking as if I could see the physical path developing in front of me, etc.
To others though, I can seem quite "out there" at first, like very abstract and contemplative. It's only after a while that they notice how structured my thought process is, and how focused I actually am. I can go off on tangents and be conscious of doing so, coming back to the last crossroad of the path a few minutes later, again quite consciously. On the con side, again, sometimes I feel like I'm too linear and not "creative" enough in my thought patterns. It's like only a few things - symbols, really - fundamentally grab me, and I spend my life more or less circling around them, always returning to them from a different stance.