Try this:

Treat everyone you meet as if you know it will be their last day on earth, and the last time you will see them, --even if they do not know this themselves.

The above is a variation on the Golden Rule and I thought it was an interesting variation. Here are some other thoughts on the Golden Rule that have been taken from the Versions of the Golden Rule Websites. 

Bahá'í Faith:
"Ascribe not to any soul that which thou wouldst not have ascribed to thee, and say not that which thou doest not." "Blessed is he who preferreth his brother before himself." Baha'u'llah

"And if thine eyes be turned towards justice, choose thou for thy neighbour that which thou choosest for thyself." Epistle to the Son of the Wolf. 1

Brahmanism:

"This is the sum of Dharma [duty]: Do nought unto others which would cause you pain if done to you". Mahabharata, 5:1517 "

Buddhism:

"...a state that is not pleasing or delightful to me, how could I inflict that upon another?" Samyutta NIkaya v. 353

Hurt not others in ways that you yourself would find hurtful." Udana-Varga 5:18

Christianity:
"Therefore all things whatsoever ye would that men should do to you, do ye even so to them: for this is the law and the prophets." Matthew 7:12, King James Version.

 "And as ye would that men should do to you, do ye also to them likewise." Luke 6:31, King James Version.
"...and don't do what you hate...", Gospel of Thomas 6. The Gospel of Thomas is one of about 40 gospels that circulated among the early Christian movement, but which never made it into the Christian Scriptures (New Testament).

Confucianism:

 "Do not do to others what you do not want them to do to you" Analects 15:23
 "Tse-kung asked, 'Is there one word that can serve as a principle of conduct for life?' Confucius replied, 'It is the word 'shu' -- reciprocity. Do not impose on others what you yourself do not desire.'" Doctrine of the Mean 13.3

 "Try your best to treat others as you would wish to be treated yourself, and you will find that this is the shortest way to benevolence." Mencius VII.A.4
 

Ancient Egyptian:
"Do for one who may do for you, that you may cause him thus to do." The Tale of the Eloquent Peasant, 109 - 110 Translated by R.B. Parkinson. The original dates to circa 1800 BCE and may be the earliest version of the Epic of Reciprocity ever written.

Hinduism:

 This is the sum of duty: do not do to others what would cause pain if done to you. Mahabharata 5:1517

Islam:

"None of you [truly] believes until he wishes for his brother what he wishes for himself." Number 13 of Imam "Al-Nawawi's Forty Hadiths." 3

 Jainism:

"Therefore, neither does he [a sage] cause violence to others nor does he make others do so." Acarangasutra 5.101-2.

"In happiness and suffering, in joy and grief, we should regard all creatures as we regard our own self." Lord Mahavira, 24th Tirthankara
"A man should wander about treating all creatures as he himself would be treated. "Sutrakritanga 1.11.33

Judaism:
"...thou shalt love thy neighbour as thyself.", Leviticus 19:18
"What is hateful to you, do not to your fellow man. This is the law: all the rest is commentary." Talmud, Shabbat 31a.
"And what you hate, do not do to anyone." Tobit 4:15 4