Sparing, frugal, thrifty, economical can all mean exercising or manifesting careful and unwasteful use of one’s money, goods, and resources.
Sparing connotes abstention or restraint.
Frugal suggests the absence of all luxury and lavishness especially in food and ways of living and dress; positively it implies simplicity, temperance, and, often, content.
Thrifty implies industry, good management, and prosperity as well as frugality.
Economical often is used interchangeably with thrifty when the sparing use of money and goods is emphasized. However the word often implies more than saving, for its chief implication is prudent management or use to the best advantage, without waste, and it is therefore far more widely applicable than thrifty, which refers only to persons or their expenditures.