Financial markets' turmoil hasn't slowed down some retirees' spending train, but it should, experts say.

Just when the holiday bills are looming like a bad hangover, portfolio values are retreating, which should be a wake-up call to trim withdrawals, but that isn't happening, said Mari Adam, a financial planner in Boca Raton, Fla.

"Last year, returns were flat, and I'm starting to see some familiar patterns" to how some clients responded to the 2008 financial crisis, she said. "That was a horrible year, but the people who went into it with good financial habits came through it and are better than ever. Others got destroyed and never bounced back."

Just what is overspending? There are myriad theories about safe withdrawal rates from retirement portfolios. Many start with a percentage of total assets in the first year of retirement, say 4 percent, and then adjust that figure for inflation thereafter, regardless of what happens in the market. Others take a more dynamic approach that allows for slightly higher withdrawals early on, but with the caveat that retirees may need to pull back if markets underperform.

Adam generally advises clients to withdraw 4 percent of last year's ending portfolio balance but adjusts that as needed depending on circumstances and investment performance. For elderly clients in their 80s, for example, she typically recommends taking the required minimum distribution amount from retirement accounts.

She doesn't quibble with younger retirees who are spending slightly more than 4 percent in any given year. It's the ones spending well above the guidelines that have her worried, she says.

Pre-retirees can make a huge impact on their savings rates by automating retirement plan and taxable savings account contributions, but adopting a mindful approach to spending helps both savers and retirees, said Liz Davidson, founder of Financial Finesse, an online financial guidance service.

People have identities with their food choices that help them set boundaries and ward off temptation, she notes. Vegans, for example, learn to not be tempted by a burger.

You might consider yourself an investment-oriented person so you don't want to spend much on things that depreciate, she says. Or you're a bargain hunter, so you just rarely pay retail.

Commit to conscious decisions about spending, she adds, and a more appropriate withdrawal rate will follow.

Janet Kidd Stewart writes for the Chicago Tribune