Yes, my Brother.
Both in sleep and in the waking world. First of all, in some of my Hubs, I have touched on the necessaries: Gratitude, purity, selfless service or soulful self-giving .. human nature does not and cannot grow with giving of one's inner self to others.
There are also necessities like receptivity, assimilation, silence, that is to say, quiet times that help us, like in the early hours of morn or night. Then nature is at its most peaceful.
A deep inner cry, aspiration or yearning for God is paramount, without which nothing can be gained. Once, through self-effort and accompanied by Grace, one does all that one is supposed to do, then Grace will come at it's own time and choosing.
There is a chapter in my book, (Chpt 3), available on amazon.com, My Guru, Sri Chinmoy: Life And Teachings. There I talk about spiritual experiences in great detail. God's force or power or Grace or Light, call it what one wills, comes into a receptive heart through prayer and meditation. The inner vessel must be receptive, and for this inner purity is essential. Again, one will receive only in so far as the inner vessel can hold. Grace can also be sudden and may be felt anywhere. Still, it is always the inner preparation that will eventually lead to this.
The Spirit manifests through peace, love, tears or joy ... and infinitely more. It cannot be contained. What varies most is the depth of the experience. Sometimes it's strong and lasting, and at other times very short. It is never painful, never sensational and encourages love not only for the individual experience, but for humanity itself. Read my book, if you can. Chpt 13, the chapter on Purity, is essential for those of us wishing to receive His Grace.