Thinking of being in G-d’s constant presence:
To think of G-d immediately upon awakening: [Immediately upon awakening, in order for one to overcome his inclination and motivate himself to get out of bed with alacrity], he should [accustom himself to immediately] think about who he is lying before and how G-d is constantly standing over him. He should contemplate how if he were to lie in the presence of a king of flesh and blood it would be considered a capital offense, and even more so here that he is lying before the King of all Kings.
One acts differently upon having the realization of G-d’s presence: [This is a great rule in the Torah and in the levels of the righteous which walk before G-d], that when one views himself in G-d’s constant presence, one acts in accordance to him being in the presence of the king. Just like ones speech and actions in front of a king differs from how they would be were he to be alone, so much more so will his actions be different when he realizes that he stands before the king of all kings. This realization immediately enters into a person’s heart a constant fear, submission, and bashfulness of the awe of G-d. [One should therefore think about this matter in all of his dealings and actions.]
What should one do if the thought of G-ds presence does not stir him? If one does not begin having these feelings right away then he needs to contemplate in this for longer periods of time and in greater intensity until he begins to feel it. As well one should do Teshuvah on ones sins, as sins prevent a person from feeling fear of G-d, as the verse states “Your sins separate between you and I“.
Immediately upon awakening one should think how G-d is constantly standing over him, and how it is unbefitting to remain lying before the King. This realization should immediately enter into a person’s heart a constant fear, and bashfulness of G-d. If one does not begin having these feelings right away he needs to contemplate in this for longer periods of time and in greater intensity until he begins to feel it. As well one should do Teshuvah on ones sins, as sins prevent a person from feeling fear of G-d.
How is one to fulfill the verse of Shivisi Havaya Linegdi Samid if he must learn Torah and work which involves having other matters on his mind?
The command is not to constantly think of G-d’s presence on ones conscious mind, as one is required to think of other matters as well. The intent is that one should be so permeated with the knowledge of G-ds constant presence that whenever a challenge arises one automatically remembers that G-d is before Him. Thus G-d’s presence is always on his subconscious mind, ready to be made conscious.
Picturing the name of Hashem in one’s mind:
It is written in the name of the Arizal that one should accustom himself to vision the letters of the name of Hashem [Yud Kei Vav Kei] in his mind as this is of great assistance in bringing a person to fear of G-d.
Sparks of Chassidus
The first thought of the day sets the tone for the entire day:
Just like the order in expression of one’s self is thought, speech and action, and ones speech is an outcome of thought, so too it is with regards to the first thought and speech that one has when he wakes up. The first thought and speech one has upon awakening sets the tone for all the thought and speech of that day. Therefore the first thought and speech that one has upon awakening is to be of matters of holiness, in order to draw this holiness into all his thought and speech of that day.
In order to awaken like a Jew one must go to sleep like a Jew:
In order for one to wake up with the proper thoughts one must go to sleep with the proper thoughts. Thus the start of a good day which is imbued with joy and spiritual matters is dependent on the order one follows prior to sleep. Hence one should think of spiritual matters prior to going to sleep as is accustomed to do when one says Kerias Shema Sheal Hamita.
 Basra 1/4, Kama 1/1; Siddur
 Basra ibid; Siddur
 As the verse states “And the entire earth is filled with his glory”. [Basra ibid] or As the verse states “Do I not fill the heavens and the earth states Hashem” [Kama ibid] The Kama and Basra quote different versus as a source for the idea of G-d standing over person. To note the Chassidic explanation of the difference between these two versus that the verse brought in Basra refers to G-d’s revelation of Mimalei Kol Almin [the personal and internal G-dly energy which he infuses into every creation according to its level] and the verse in Kama which refers to Soveiv Kol Almin [the encompassing G-dly light which surrounds every creation equally]. [See Torah Oar 16a; 94b; 123b] To note that in Kama 1/2 Admur quotes the same verse as the Basra regarding this matter. Vetzaruch Iyun.
 Basra 1/5, Kama 1/2
 Basra 1/5; As the verse states “Shavisi Havaya Linegdi Samid”
 One cannot compare his form of dwelling, dealings and movements when he is in the privacy of his home to the way they are when he is in front of a great king. Likewise ones speech and form of conversation when he is with his family and relatives cannot be compared to his form of speech when he is before a king. This certainly applies when he contemplates that he is before Hashem the king of all kings is standing over him and sees his actions, as the verse states “if man conceals his actions will I not see it says Hashem” and “his glory fills all the earth”. [Kama and Basra ibid with a slight difference that in Kama the verse of “his glory” precedes the verse of “if man”.]
 Kama ibid
 Basra 1/5
 Beir Heiytiv 1/2; Kaf Hachaim 1/2 in name of Shaar Ruach Hakodesh 21; Ketzos Hashulchan 144 footnote 6 states that his uncle Reb Dovid Tzevi Aryeh Schneerson told him that the Gaon of Brisk would periodically write the name of Hashem in the air in order to fulfill the verse of “Shavisi Havayah Linegdi Samid”.
 Keser Shem Tov teaching 212; Igara Depirka 205; Derech Pikudecha 18/5; Shulchan Hatahor 3
 So is the accustomed saying amongst Chassidim, brought in Arugas Bosem 1/1 in name of Rav Meir of Parmishlan; This explains why the Rama [1/1] writes that when one lays in his bed to go to sleep he should know before whom he is lying as this will affect how he will awaken the next morning.