Fan Lihong, her parents and her daughter are standing along Madang Road in Shanghai, cups in hand. Many others in the line are doing the same.

From afar, such a scene might seem reminiscent of water rationing. But these individuals are simply after a caffeine fix, with sustainability in mind.

"I have been using my own cups to buy coffee this year. Using my own cup is not only convenient and cost effective－it also helps with environmental protection," says Fan.

Another customer who was waiting in a line outside Manner Coffee, Liu Shiyun, echoes the same sentiment.

"A latte at Manner Coffee costs 15 yuan ($2.24). If I use my own cup to buy the coffee, I get 5 yuan discount and will save at least 100 yuan per month," Liu says.

"I hope more coffee shops can promote this concept as it is environmentally friendly and cost-effective."

Manner Coffee, which operates over 100 stores across China, sells nearly 100,000 cups of coffee per day. Around half of their customers bring their own cups, according to Ning Yihan, marketing representative of Manner.

"We started to encourage consumers to bring their own non-disposable cups to Manner stores since the day we were established. We hope to contribute to environmental protection with our customers," Ning says.

"It is very interesting and meaningful while you see all kinds of people bringing their own cups. There are Japanese-style izakaya store owners bringing beer mugs and security or sanitation workers with their thermoses," she adds.

For others like Ping Jing, a 26-year-old nurse who usually buys her coffee from Writer Coffee on Weihai Road, using her own mug is not just about cutting down on costs, but taste as well.

"A glass cup or mug will give you a different taste and an exclusive feel compared with using the disposable paper cup," she says.

"More people are drinking coffee today. We don't just wish to drink coffee－we also hope this habit can be environmentally friendly."