From a passenger's perspective, AIRHOSTIE's tips are spot on... if you work for one of the middle ranking airlines (BA, Qantas, etc) you will fit in well if you follow them.
However, if you have the good fortune to work for one of the top ranking airlines (in most passenger surveys), e.g. SQ or CX, then then points 1) and 5) don't really work. To fit in there you DO need to be happy and smiling pretty much all of the time, and, particularly if you work the J or F cabins then you are there to satisfy the passenger's every reasonable whim.
Pretty well all major airlines reach acceptable levels of safety - what differentiates the best airlines is the level of such service, and that is main reason why I will often go some way out of my way to fly CX (or SQ). At the end of the day it is the customers in the premium cabins who contribute the greater part of your salary and your primary role as cabin crew is to make us get off the plane wishing the flight hadn't come to an end. That happens for me about 80% of the time on CX, and about 10-20% on BA/AA/QF.