God instructs us how to address our supplications to Him in the Holy Quran clearly so that we do not need any further explanation, Call upon your Lord (O humankind) with humility and in the secrecy of your hearts. Indeed your Lord does not love those who exceed the bounds. (Keep within the bounds He has decreed:) Do not cause disorder and corruption on the earth seeing that it has been so well ordered, and call upon Him with fear (of His punishment) and longing (for His forgiveness and mercy). Gods mercy is indeed near to those devoted to doing good, aware that God is seeing them. (Al-Araf Surah, 7:55, 56)
Remember and mention your Lord within yourself (in the depths of your heart), most humbly and in awe, not loud of voice, at morning and evening. And do not be among the neglectful. (Al-Araf Surah, 7:205) And, also God forbids us not to supplicate by becoming proud and arrogant, to supplicate in a screech tone by raising hands excessively and He orders us to supplicate in a humble, and doleful way with a soft voice. Those who are in your Lords Presence never turn away from His service out of pride, and they glorify Him, and prostrate before Him. (Al-Araf Surah, 7:206) Human beings are only allowed to address their supplications to God. That is to say, God is the only One that humans can make a request , no one else, because, To Him alone is made the call of truth and the prayer of truth addressed. Those to whom they invoke and call others (to invoke), apart from Him, cannot answer them in any way – (so that he who invokes them is but) like one who stretches out his hands to water (praying) that it may come to his mouth, but it never comes to it. The prayer of the unbelievers is but destined to go to waste. (Ar-Rad Surah, 13:14) The most admirable and blessed time of supplication in the view of God is when everyone is sleeping or doing else. Elders always have waited for such times to supplicate. Prophet Muhammad (peace be upon him) too, made his supplications of general importance after nighttime prayers. By laying all unawareness, and sleeping aside, invoking cause you to become closer to God. Their sides forsake their beds at night, calling out to their Lord in fear (of His punishment) and hope (for His forgiveness, grace, and good pleasure), and out of what We have provided for them (of wealth, knowledge, power, etc.,) they spend (to provide sustenance for the needy and in Gods cause, purely for the good pleasure of God and without placing others under obligation). (As-Sajdah Surah, 32:16)