A short Method of Meditation. And first, the Presence of God, the First Point of Preparation.
IT may be, my daughter, that you do not know how to practise mental prayer, for unfortunately it is a thing much neglected now-adays. I will therefore give you a short and easy method for using it, until such time as you may read sundry books written on the subject, and above all till practice teaches you how to use it more perfectly. And first of all, the Preparation, which consists of two points: first, placing yourself in the Presence of God; and second, asking His Aid. And in order to place your self in the Presence of God, I will suggest four chief considerations which you can use at first.
First, a lively earnest realisation that His Presence is universal; that is to say, that He is everywhere, and in all, and that there is no place, nothing in the world, devoid of His Most Holy Presence, so that, even as birds on the wing meet the air continually, we, let us go where we will, meet with that Presence always and everywhere. It is a truth which all are ready to grant, but all are not equally alive to its importance. A blind man when in the presence of his prince will preserve a reverential demeanour if told that the king is there, although unable to see him; but practically, what men do not see they easily forget, and so readily lapse into carelessness and irreverence. Just so, my child, we do not see our God, and although faith warns us that He is present, not beholding Him with our mortal eyes, we are too apt to forget Him, and act as though He were afar: for, while knowing perfectly that He is everywhere, if we do not think about it, it is much as though we knew it not. And therefore, before beginning to pray, it is needful always to rouse the soul to a stedfast remembrance and thought of the Presence of God. This is what David meant when he exclaimed, “If I climb up to Heaven, Thou art there, and if I go down to hell, Thou art there also!”  And in like manner Jacob, who, beholding the ladder which went up to Heaven, cried out, “Surely the Lord is in this place and I knew it not”  meaning thereby that he had not thought of it; for assuredly he could not fail to know that God was everywhere and in all things. Therefore, when you make ready to pray, you must say with your whole heart, “God is indeed here.”
The second way of placing yourself in this Sacred Presence is to call to mind that God is not only present in the place where you are, but that He is very specially present in your heart and mind, which He kindles and inspires with His Holy Presence, abiding there as Heart of your heart, Spirit of your spirit. Just as the soul animates the whole body, and every member thereof, but abides especially in the heart, so God, while present everywhere, yet makes His special abode with our spirit. Therefore David calls Him “the Strength of my heart;”  and S. Paul said that in Him “we live and move and have our being.”  Dwell upon this thought until you have kindled a great reverence within your heart for God Who is so closely present to you.
The third way is to dwell upon the thought of our Lord, Who in His Ascended Humanity looks  down upon all men, but most particularly on all Christians, because they are His children; above all, on those who pray, over whose doings He keeps watch. Nor is this any mere imagination, it is very truth, and although we see Him not, He is looking down upon us. It was given to S. Stephen in the hour of martyrdom thus to behold Him, and we may well say with the Bride of the Canticles, “He looketh forth at the windows, shewing Himself through the lattice.”
The fourth way is simply to exercise your ordinary imagination, picturing the Saviour to yourself in His Sacred Humanity as if He were beside you just as we are wont to think of our friends, and fancy that we see or hear them at our side. But when the Blessed Sacrament of the Altar is there, then this Presence is no longer imaginary, but most real; and the sacred species are but as a veil from behind which the Present Saviour beholds and considers us, although we cannot see Him as He is.
Make use of one or other of these methods for placing yourself in the Presence of God before you begin to pray;—do not try to use them all at once, but take one at a time, and that briefly and simply.[From 'Introduction t the Devout Life', Part Two, by St. Francis de Sales. Public Domain.]