Look into the mirror. Usually, we look away quickly, perhaps embarrassed or not wanting to face the fact that who we see reflected there is but a stranger to us. But, try it: face the face before you.
At first, we might be preoccupied with observing our facial features but it won't take long to tire of this, for it reveals little of ourself.
We do this all the time during the day when, for example, we wonder where we left our car keys, or what time was that appointment. We might also knit our eyebrows and purse our lips in sudden consternation of something important we may have forgotten. At such times, the mind begins to search on "the hard disk" of memory and tells the monkey to "shut up for a sec."
It's the kind of concentration as most experience in watching a good movie (though not an edge-of-the seat thriller). Or, the kind you might experience while ice skating, skiing, or in the zone where body and mind are one-pointedly focused, both relaxed but keenly engaged at the same time.
It has to be something you want to do; that you've been waiting all day to find the time and opportunity to do. It has to be something you enjoy; something that takes and gives you energy, joy and flow!
Paramhansa Yogananda put it bluntly: "The soul loves to meditate; the ego HATES to meditate."
"By steadfast meditation on Me" (Bhagavad Gita) we come quickly to this portal through which inspiration, insight, wisdom, joy, love, and "all these things added unto you" pour forth into our body, mind, and our life.
You have nothing to fear from entering the "thoughtless-zone." No one or nothing will come to sweep you away into the abyss. You need only "to be present to win." (Stay conscious, in other words!) Indeed, wouldn't it be wonderful if Divine Mother came to scoop us out of our delusion! No, She wants only our love; the only thing she doesn't possess and only we can give it: willingly, consciously. Union with the Infinite must be sought and won by earnest effort, attunement with divine consciousness, and the grace of God and guru.
Go then through your day, then, with the eyes of awareness; non-judgement; with the all-seeing-I. Fear not the journey of awakening. You can take lifetimes or move switfly to the goal. It's always up to you.
NB: the state beyond thought can come "like a thief in the night" with or without apparent intention or cause. The description given above is simply an explanation with a recipe. But the state of pre-thought consciousness knows no boundaries. By devotion, self-giving, and in any number of triggering activities, mundane, spiritual or meditative, it can steal upon us. So long as we remain conscious and present, no harm can ever come to us.