List of means for an accepted Du’a

بسم الله الرحمن الرحيم

al-Rāzī said in his Tafsīr (3/622):
“The nations have agreed that (mere) supplication with the tongue that is empty from self-desire and little effort (from the person), has no impact”

Actions which help in acceptance of Du’a:

Having Waḍū (al-Bukhārī 6383)
Turning to Qiblah (al-Bukhārī 6343)
Raising hands towards the sky (al-Bukhārī 6341 and Abū Dawūd 1486)
Praising Allah and sending Ṣalawāt upon the Prophet ﷺ before du’a (Ḥasan Isnād in Abu Dawūd 1481, al-Tirmidhī 3477 & al-Nasāī 1285)
Mentioning Allah’s greatest name which is Allah (Ṣaḥīḥ Isnād in Abu Dawūd 1493 & al-Tirmidhī 3475)
Saying the Du’ā of Yūnus عليه السلام which is:
لَا إِلَهَ إِلَّا أَنْتَ سُبْحَانَكَ إِنِّي كُنْتُ مِنَ الظَّالِمِينَ
(Sūrat al-Anbiyā 21:88 and al-Tirmidhī 3505 with Ṣaḥīḥ Isnād)
Asking Allah with your righteous actions (al-Bukhārī 2215 & Muslim 2743)
Asking Allah with His Names and Attributes (Sūrat al-A’rāf 7:180)
Asking a righteous person to make Du’a for you (al-Bukhārī 1010)

People whose Du’a are accepted:

Fasting person
The just leader
The oppressed one (with Ḥasan Isnād in al-Tirmidhī 3598 and Ibn Mājah 1752)
The father
The traveler (al-Tirmidhī 1905 & Abū Dawūd 1536; Ḥasan)
When a Muslim makes Du’a behind his brother (Muslim 2732)
When children make Du’a for their parents (Ibn Mājah 3660 with Ḥasan Isnād)

Times where Du’a is more likely to be accepted:

Last one third of the night (al-Bukhārī 1145 & Muslim 758)
After ‘Asr on Friday (al-Bukhari 935 & Muslim 852 & Abū Dawūd 1048 with Ṣaḥīḥ Isnād)
After Adhan
During calamity (Abu Dawūd 2540; Ṣaḥīḥ)
Between Adhan and Iqamah (Abu Dawūd 521, al-Tirmidhī 212; Ṣaḥīḥ)
Upon hearing the rooster at night (Musnad Ahmad 8064; Ṣaḥīḥ)
Between Dhuhr and ‘Asr on Wednesdays (al-Adab al-Mufrad 704; Ḥasan Isnād)
During sujood in prayer (Muslim 482)
Before Salam in prayers (Muslim 402)
When prayer is established
When ranks of battle during Jihad is set (Musannaf ibn abi shaybah 31204; Ṣaḥīḥ Isnād)