I learned something very important from this:

首先定力要强，基本原则：买了不后悔，后悔不要买。购物之前，一定列好清单，计划外的东西再好也不买！记住，东西是一辈子也消费不完的，永远都有好东西。所以只买你现阶段需要的东西就好。

Also, "buy what you need, not what you want." 

It's also good to hear that you manage daily expenditures in spreadsheet, that's better than doing nothing.