Ihsan: “it’s to worship Allah as you are seeing Him and while you see Him not yet truly He sees you.” This is the Prophet’s definition of the term “Ihsan”, and it signifies that a person, who is characterized with Ihsan, does everything perfectly as he sees his MASTER watching him.
Shedding more light on the concept of Ihsan, Dr. Muzammil H. Siddiqi, former President of the Islamic Society of North America, states in a Khutbah at ISOC – Rabi Al-Thani 24, 1423/ July 5, 2002:

Allah, Most High, says: (Nay, whoever submits his whole self to Allah and is a doer of (Ihsan) good he will get his reward with his Lord; on such shall be no fear, nor shall they grieve.)(Al-Baqarah 2:112)
(Allah commands justice, (Ihsan) the doing of good, and liberality to kith and kin, and He forbids all shameful deeds, and injustice and rebellion: He instructs you, that you may receive admonition.)(An-Nahl 16:90)
(Serve Allah, and join not any partners with Him; and do (Ihsan) good to parents, kinsfolk, orphans, those in need, neighbors who are near neighbors who are strangers, the companion by your side, the way-farer (you meet) and what your right hands possess: for Allah loves not the arrogant, the vainglorious.)(An-Nisa’ 4:36)
There are three important concepts of Islam: Islam, Iman and Ihsan.
1. Ihsan is one of the most important principles of Islam. The Qur’an has more than 66 verses on this subject. Actually the whole Qur’an guides to Ihsan, which means doing everything in an excellent manner and it also means doing the acts of charity and kindness.
2. The best definition of Ihsan comes in a Hadith, in which the Prophet, peace and blessings be upon him, says: “(Ihsan is) it’s to worship Allah as you are seeing Him and while you see Him not yet truly He sees you.” (Al-Bukhari, Hadith No. 48)
Ihsanincludes many things as follows:
1. In prayers and in relation to Allah, feel His presence.
2. In relations to parents, honor them, be thankful to them and do your duties towards them.
3. In relations to other relatives, recognize their rights, be good to them and help them if they need help.
4. In relations to people in society who are weak, needy and poor, be charitable and nice to them.
5. In human relations in general, be good to others. Even those with whom you disagree in matters of faith, present to them the message, but have no aggression towards them:
(But because of their breach of their Covenant, We cursed them, and made their hearts grow hard: they change the words from their (right) places and forget a good part of the Message that was sent them. You will not cease to find them – barring a few – ever bent on (new) deceits. Pardon them, then, and overlook (their misdeeds): for Allah loves those who are kind.)(Al-Ma’idah 5:13)
6. In relations to the whole world including vegetables, animals and even inanimate things, do not waste, do not misuse or abuse and be thankful to Allah.
(Do no mischief on the earth, after it has been set in order, but call on Him with fear and longing (in your hearts): for the Mercy of Allah is (always) near to those who do good.)(Al-A`raf  6:56)
The Prophet, peace and blessings be upon him, said, “Allah has prescribed that you do everything in an excellent and nice manner.” (Muslim, Hadith No. 3615)
7. Finally, Just do good, because Allah loves those who do good things:
(But do good; for Allah loves those who do good.)(al-Baqarah 2:195)