tighten (one's) belt

Translations
затянуть (свой) пояс
With the recent economic downturn, many families have had to tighten their belts.
Из-за недавнего экономического спада многим семьям пришлось затянуть пояса.
Definitions
To reduce one's spending or to live more frugally, often due to financial constraints or economic difficulties.