Tipping or in its purest form- to help a service provider or one in need to survive in the daily struggle to live, is only common from those whom have a big heart & able to give & survive.
How much should one tip or give aid?
In USA, most of whom are big hearted folks, of which helped & influenced our nation success & progress in many, many ways for decades, tips & finance for charity causes are usually at 10% for service or aid to be provided, which leaves one to survive, cause if we cant survive, then we cant help others.
To help our neighboring Asian countries fellow Humans, which had a lack of leadership & commitment/opportunities to their citizens, a form of voluntary Redistribution of Wealth to those in needs, we Sporeans only need to look at the daily wage of a fellow human in that particular nation.
In Vietnam, which is a majority on social passes now, it is USD $150/mth = USD $5/day.
In Thailand, it is USD $10 per day.
Based upon knowledge learnt from successful Asian neighbors & once superpowers in Singapore, on their needs for a sustainable life-
Indians-would save EVERY penny to their death
Chinese - would take risks but expect $3 for every dollar spent
Westerners, especially Americans - risk it all, spend big & earn big, or go broke in flames of glory.
So, if women denied of opportunities from their homeland, & seek better opportunities in life here, they would in economic sense, want at least to earn 3 times their salary per day elsewhere, being asians.
Thus, if they are given tips 3 times of their daily avg wage, they would be satisfied on a psychological sense, as probably at least 1 X time of their wage would pay for opportunistic mamasan & living costs-packed rental & meagre food for the duration of their stay = minus overheads, USD$20 A DAY / NOT PER PERSON, for Vietnamese from ALL customers where they work, or USD$40 a day for a thai. Anything more is a bonus daily. ( USD $1 = S$ 1.35cts)
The only ones who would not agree to such tip fees are the opportunistic mamasans, whom may had foolishly paid S$20k to S$40k to their nation's middlemen & local black market conmen to 'ease' the way for their girls thru their connections, to come here to seek financial aid, as these aged mamasans want to recoup their costs, live off the girls earnings, without realizing that Spore is the lowest in International Corruption index, unlike other nations such as Malaysia, Dubai, etc without the need for bribes to anyone in Spore, & had only been duped by conmen, being new in a foreign land to their own
Point is - As we Sporeans had been taught to study & work hard & smart, succeeded in transforming our nation from a mere trading outpost, left for dead, but by sweat & tears & rolled up sleeves to the success of today, may we all now also learn to play smart, especially the vulnerable & the lonely hearts. Our principle in life is to Hurt no one & do not be hurt by anyone.