I, too, am a natural mystic. That is to say, I wasn't consciously following any set of practices and had no teacher when I experienced the illumination of fire and the lesser mystical states that lead up to it. However, in examining my own life, I can see that there was a path that I was following by "accident." It is a path in the sense that spending a lot of time in certain lesser mystical states prepares one for the illumination of fire.
The two lesser states are "day-dreaming" and "being in a receptive state" while experiencing solitude in nature. Probably almost everyone has experienced these states. For instance, when do you get your best ideas? While washing dishes? Commuting to work? On your daily walk? I'll bet it is while doing something comfortably monotonous, which one can do without paying attention, thus letting the mind roam free. And isn't it a glowing, luminous kind of state, a minor state of ecstasy? Those are the marks of a mystical experience.
Thus, the meditation practice I advocate is just the opposite of the popular Buddhist types of meditation. Do not sit still. Do not concentrate on anything. The day-dreaming state is the very opposite of concentration. It is only when mind and soul are free that they can wander into other realms of consciousness. Concentration will never work.
Nature mysticism becomes possible when one has spent a lot of time day-dreaming. So day-dreaming is the first step on the path, nature mysticism is the second, and the illumination of fire the third. I found the endless sighing wind of the prairie the most conducive for communion. For others, it might be the endless crashing of waves on a seashore. Or the sighing of trees in a forest. Again the signs of communion are a glowing, luminous, somewhat ecstatic state of mind. One absorbs the mood of the place. However, if you think the wind, or the mountains or the sea speaks to you, you are hallucinating. Symbolism or verbal thoughts are quite absent in the consciousness of nature. So my second piece of advice on meditation is to spend a lot of time in solitude in nature. Don't concentrate. Don't think. Just absorb the mood of the place, or the wind, or the sea.
Clearly, the most important requirement for most people who wish to become mystics, is a change in lifestyle. Get far away from cities or towns. Learn to enjoy solitude (this is another mark of the mystic, who is never bored with his or her own company). Find yourself some simple tasks which you can do automatically. "Carrying wood and water," is what the Taoist mystics called this path. And, as a child, I did carry wood and water, since we had a wood burning stove and no running water. The pump was a good hundred yards from the house. It is difficult to find such conditions today.
The person who is constantly worried about something, constantly scheming about something, will never become a mystic. Don't worry. Don't hurry. And that too, requires a change in lifestyle. The people least likely to ever know an ecstatic moment are those driven and harried workaholics whose goal only seems to be the accumulation of things.
By contrast, the mystic is always trying to get rid of the accumulation of things. Possession works both ways. Do I own the car, or does it own me? Do I own the house, or does it own me? If you want to know how it is physically possible to pursue the ecstacy of the mystic, read the chapter on "The Seeker."