What are the morning and evening adhkar?

When to say them

• Morning: after Fajr until sunrise is the best time; many scholars allow until mid-morning.
• Evening: after Asr until Maghrib is the main view; some scholars extend it into the early night.
• Missed it? Say them when you remember. Late is better than never.

A starter set for beginners

• The three Quls, 3 times each: Surah al-Ikhlas, al-Falaq and an-Nas. The Prophet ﷺ told a Companion to say them "three times in the morning and evening; they will serve you for every purpose" (Sunan Abi Dawud 5082).
• Bismillahil-ladhi la yadurru ma'asmihi shay'un fil-ardi wa la fis-sama'i wa huwas-sami'ul-'alim (3 times): "In the Name of Allah, who with His Name, nothing in the earth or the heavens can cause harm, and He is the Hearing, the Knowing." Whoever says it three times in the morning and evening, "nothing shall harm him" (Jami' at-Tirmidhi 3388; also Sunan Abi Dawud 5088).
• SubhanAllahi wa bihamdihi (100 times): "Exalted is Allah... and all praise is due to Him." Whoever says it a hundred times in the morning and evening brings nothing better on the Day of Resurrection, except someone who said the same or more (Sahih Muslim 2692).

If 100 feels like a lot, start with 10 and build up. See What does "SubhanAllah" mean and when do I say it?

Adding the longer ones

• Sayyid al-Istighfar: the Prophet ﷺ called it "The most superior way of asking for forgiveness from Allah" (Sahih al-Bukhari 6306). It begins "Allahumma anta Rabbi la ilaha illa anta", and he promised Paradise to someone who says it with firm faith in the morning or evening and dies before the next evening or morning.
• The evening greeting: Ibn Mas'ud reported that each evening the Prophet ﷺ said "We entered upon evening and the whole Kingdom of Allah also entered upon evening and praise is due to Allah", followed by a dua for the good of the night (Sahih Muslim 2723). In the morning, the same is said with "morning".
• Ayat al-Kursi: many people include it too. See What is Ayat al-Kursi and when do I recite it?

These longer ones are easiest to learn from a booklet or app. Popular choices include "Fortress of the Muslim" (Hisn al-Muslim), which has Arabic, transliteration and translation side by side.

Making it stick

Tie the morning set to something fixed, like sitting on your prayer mat after Fajr or your first coffee. Tie the evening set to Asr or your commute home. Reading from a phone or paper is fine. Add one new dhikr only when the previous ones feel easy.