One of the them is by supplication with hope as supplication is ordered to and promised to answered as he said,
"Your Lord said, "supplicate to me; I will respond." [Quran, 40:60]
In the four Sunans from Al-Numan Ibn Bashir from the Prophet (may Allah bestow peace and blessings upon him) said,
"Supplication is worship." [Tirmidhi & Ahmad]
Then he recited this Quranic passage. In another hadith reported by At-Tabarani (raised report),
"Whoever is given supplication is bestowed a response because Allah, The Exalted, said, "Supplicate to me; I will respond." And in another Hadith,
"Allah does not open, to his servant, the gates of supplication and lock the gates of response upon him."
Although supplication causes a necessary response upon completion of its prerequisites and (overcoming) select obstacles. There is a difference in response according to some of its conditions or the presence of some obstacles and their etiquettes. We have mentioned some of its conditions, obstacles, etiquettes in the commentary of tenth Hadith. [The tenth hadith of Imam An-Nawawi’s collection of forty hadith]
As is reported At-Tirmidhi in a hadith from Abu Hurayrah (may Allah be pleased with him) he narrates that the Prophet (may Allah bestow upon him peace and blessings) said,
"Supplicate to Allah whilst certain of a response and Allah does not accept a supplication from a heedless heart." [Tirmidhi]
In Al-Musnad it is reported from Abdullah Ibn Umar (may Allah be pleased with them) that the Prophet (may Allah bestow peace and blessings upon him) said,
"These hearts are containers and others are contained. When you ask Allah ask him and be certain of a response as Allah does not respond to a servant's supplication from an outwardly heedless heart." [Ahmad]
Therefore it is prohibited for the servant to say,
"O Allah, forgive me if you wish; rather he should ask determinedly, as Allah does not dislike it." [Ahmad & Bukhari]
It is prohibited to be hasty and leave supplication in anticipation of response. This causes a delay in response until the servant is not severed from hope that the supplication is answered.
If the supplication is long as he, Glorified is he, loves insistence in supplication. A transmission relates,
"If a servant supplicates to his Lord and he loves it. He says, "O' Jibreel, do not hasten to fulfil the need of my servant as I love to hear his voice." [Tabarani]
The Exalted said,
"Call on Him in fear and hope as the mercy of Allah close onto those who do good." [Quran, 7:56]
As long as the servant is insistent in supplication; hopeful of a response without severing one from mercy then a response is close. Whoever constantly knocks on a door will have it opened to him.
In the authentic collection of Al-Hakim from Anas, raised report,
"Do not fail to supplicate as no one perishes with prayer." [Hakim]
From the most important that the servant asks form his Lord is forgiveness for his sins and like hope of salvation from the fire and to enter Paradise.
The Prophet (may Allah bestow peace and blessings upon him) said,
"Change to murmuring." [Abu Dawud, Ibn Majah & Ibn Hibban] Meaning change the question to Paradise and salvation from the fire.
Abu Muslim Al-Khawlani said,
"No supplication that occurred to me that I mentioned the hellfire in it except I sought refuge from it."