Ihsan in Intention
Ihsan in intention is a very important thing, it is an exalted good deed. You need to clean your intention of any imperfections or impurities such as hypocrisy, insincerity, betrayal, arrogance, love of fame and selfishness etc.
As for Ihsan in deeds, namely in treating people, it is not obligatory or a religious command but it is praised and rewarded by Almighty Allah. Ihsan with people, includes all the good words and deeds towards all people, except for those it is prohibited to be muhsin (good) to. This is a deep issue that requires a lot of discussions; it is classified under cases such as al-Wala' Wal Bara' (loyalty and disavowal) and al-Mawala Wal Moada (adherence and enmity).
The lowest rank of Ihsan is reflected in a hadith mentioned in Sahih Muslim and Sahih al-Bukhari (1). Narrated Abu Hurairah (RA) that the Prophet Muhammad (Peace Be upon Him) said, "A prostitute passed by a panting dog near a well and saw that the dog was about to die of thirst, she took off her Khuff (leather sock or shoe) and tied it with her head cover and drew out some water for it. So Allah forgave her because of that."
Doing an act of Ihsan towards a dog, animals or any sort of creatures is the least rank of Ihsan, yet Almighty Allah forgave a prostitute for doing such an act!!! If Allah forgives sins and bad deeds of prostitutes with his mercy and Ihsan, then can you imagine how big the reward of Almighty Allah towards believers and good doers for their faith and Ihsan. So, the concept of Ihsan embodies branches, sources and ethics of living and etiquette such as companionship, forgiveness and returning rights. Almighty Allah says (what means): “Those who spend [in Allah's Cause - deeds of charity, alms, etc.] in prosperity and in adversity, who repress anger, and who pardon men; verily, Allah loves Al-Muhsinun (the gooddoers).”(Al Imran: 134)
(1) Narrated by al-Bukhari, Ahadith Al Anbya’ (Sayings of the Prophets) (3467), Bed’ Al Khalq (Creation) (Chapter: If a fly falls in your drink..) (3321), Narrated by Muslim, Kitab Al Salam (Peace) (the Bounty of giving water and food to animals) (2245)