This is one of the easiest ways to gain treasures of reward. You can make dhikr wherever you are, at all times. You can make dhikr at your home, school, or workplace, and you can make it while you are driving, walking, traveling, and commuting. In addition, the Prophet (peace and blessings be upon him) gave us guidance for reciting certain formulas of dhikr that have special reward. For example, Abu Hurairah (may Allah be pleased with him) reported that the Prophet (peace and blessings be upon him) said
He who recites after every prayer: Subhan Allah (Allah is free from imperfection) thirty-three times; Al-hamdu lillah (praise be to Allah) thirty-three times; Allahu Akbar (Allah is Greatest) thirty-three times; and completes the hundred with: La ilaha illallahu, wahdahu la sharika lahu, lahul-mulku wa lahul-hamdu, wa Huwa `ala kulli shai'in qadir (there is no true god except Allah. He is One and He has no partner. His is the sovereignty and His is the praise, and He is Omnipotent), will have all his sins pardoned even if they may be as large as the foam on the surface of the sea. (Muslim)
Abu Hurairah (may Allah be pleased with him) also reported that the Prophet (peace and blessings be upon him) said;
He who says Subhan-Allahi wa bihamdihi (Allah is free from imperfection and His is the praise) one hundred times a day, his sins will be obliterated even if they are equal to the extent of the foam of the sea. (Al-Bukhari and Muslim)
Abu Ayyub Al-Ansari (may Allah be pleased with him) reported that the Prophet (peace and blessings be upon him) said;
He who utters ten times La ilaha illallahu, wahdahu la sharika lahu, lahulmulku wa lahulhamdu, wa Huwa `ala kulli sha'in qadir (There is no true god except Allah. He is One and He has no partner. His is the sovereignty and His is the praise, and He is Omnipotent), he will have a reward equal to that for freeing four slaves from the progeny of Prophet Isma`il. (Al-Bukhari and Muslim)