wow what a “heavy and deep” question apples!too
Key to my happyness is:
*Never Complaining to God (almost never because i am human being and weak)
*Tension lene ka nahin (balkeh dena ka hai 
= joke!!) because problems will not be solved when you make tension.
*Whatever happens, 10000 dollar car total loss?? no tension joh hona tha woh ho gaya abh kya kar saktay hain nothing so sleep like a baby.
*Alway alway glass is half FULL not half empty.
*Live and Let Live.
*Never be too stubborn to forgive, ONLY those should think of not forgiving when they are themselfs without any sin.
*If i disagree with someone about something does not mean i can’t be friends with them.
Its like when you have a brother or parents u disagree about many things with them but they are still your family, So why not with non family memebers, with friends, for me no differentiation.
*Always look at the bright side of life.
*Humble being humble down to earth and kick the ass of you EGO as much as you can.
*Never be afraid to forgive and ask for forgiveness.
*If someone can be extremist in hatred and violence THEN why not be extremist in Love, Forgiveness and non violence. Try to be extremist in passifism.
Khair these are some rules i try to abide by in my life. Not always i succeed but I am trying.