I would write in English, which works easier for me.
To your hair dresser/nails lady etc.--double tips
To your super of the building--$50 cash
To the news paper deliver person--$20
To the postman--$25 or a gift (USPS won't allow their employees to accept tips)
Please feel free to add the list..
我觉得可能因为习惯问题,中国人不是很注意这方面的礼貌。但是我觉得还是很重要的。