NEW YORK — When mathematics professor Annalisa Crannell needs new clothes, she doesn't head for the mall or outlet stores or even discount stores.

Crannell is an aficionado of Goodwill Industries shops. And she'll pass by the racks with $7 blue jeans and head for the bins where the jeans sell for $1. She's also happy to take friends' castoffs.

"Am I the biggest tightwad on the planet?" asks Crannell, a resident of Lancaster, Pa. "No. But I'm more frugal than most of the people I know."

A lot of people could learn from Crannell, who teaches at Franklin & Marshall College, and others who have adopted thrifty habits that they feel are both ecologically sound and help them cope with the rapidly rising costs of food, fuel and other necessities.

The word "frugal" might sound a bit old-fashioned, but the concept is as modern as today, says New York financial planner Stacy Francis.

"Keeping track of where your money goes is the most important financial task you can undertake," she said. "It really doesn't matter what you make. It matters what you spend."

She said many people didn't worry much about money when the stock market was rising, home values were soaring and the job market was solid. Those conditions have changed, and "when cash is tight, spending needs to get tighter, too," Francis said.

Some people have turned frugality into a lifestyle.

Annette and Steve Economides of Scottsdale, Ariz., try to live the life they describe in their book, "America's Cheapest Family Gets you Right on the Money."

The Economides, who don't use credit cards, believe consumers need to avoid debt, spend less than they earn and embrace a thrifty lifestyle.

The couple suggests people start on the road to frugality by making a spending plan.

"Some people think 'budget' is a four letter word," Steve Economides said. "It's not. And it's not a noun either. It's a verb. And it's an action verb."

Budgeting requires a family to estimate future spending, based on what has happened in the past, and to set aside money to cover what a family considers important, he said.

What if it doesn't look like the money will go far enough? That's where frugality comes in.

Take grocery shopping. The average American family of four spends between $800 and $900 a month on food, Steve Economides said. By shopping more carefully, a family can cut that in half, he said.

The Economides, who have four children, watch the store circulars and ads so they can stock up when items they use frequently are on sale.

For Crannell, frugal spending in some areas, like clothing, frees up money to be spent on things she cares more about.

She and her husband, Neil Gussman, invested in energy-efficient windows for their home several years ago.

She walks to work, but when she does drive it's behind the wheel of a Toyota Prius Hybrid car, which runs on gas and electricity.

Crannell likes yard sales, especially those where an entire neighborhood cooperates because there's a bigger selection. She shops at a local farmers market and sometimes makes vegetarian meals.

Crannell also believes in teaching her children the fine art of thrift shopping.

"Nigel, my 8-year-old, loves to go to yard sales with me," she said. "He can get toys for a quarter at yard sales. He has more toys than he knows what to do with."