Deduct hard expenses first: rent, water fee, electricity fee, heating fee (not considered in the south), telephone fee, bus fee (not considered within the distance from the unit residence 1 km), food fee (which can be appropriately flexible) and insurance fee (not three gold hardware, but commercial life insurance purchased freely). The younger you buy, the more economical it is.
Then plan uncertain expenses, clothing expenses, social expenses (wedding, funeral, etc. ), parents' support expenses (even if there is no expenditure, budget), money saved by buying a house, buying a car and getting married, travel and so on.
The most important thing: be sure to keep an account every day and make an account every month.