Here are three of the week's top pieces of financial advice, gathered from around the web:

Research your fund's fees
Individual investors are wasting up to $7 billion a year on "expensive index funds that are no better than cheaper funds — without even realizing it," said Gail MarksJarvis at Reuters. A study by investment research firm Morningstar found that investors tend to blindly diversify when selecting investment funds — and pay little attention to fees. The firm recently monitored a 3,600-strong group who received $10,000 to invest in identical S&P 500 index funds only distinguishable by their fees. Most participants had "no idea what to do" and followed the investment platitude to diversify across funds, meaning they spent on "needlessly expensive" options. "The study is especially disconcerting because it focuses on index funds, where the only decision is a simple one — comparing price."

Financial rules made to be broken
Financial planners are increasingly advising their clients that some once sacrosanct financial rules should occasionally be broken, said Casey Bond at HuffPost. Getting married, for instance, doesn't necessitate a merging of finances. It's now "common for marriage to happen later in life after couples have spent years building their financial lives independently." The advice to "pay off your mortgage as fast as possible" is also outdated. Mortgage rates remain historically low, and many investments generate returns above 8 percent, so you should focus on making on-time payments and seeking out higher returns. Using your age to determine your asset allocation between stocks and bonds is another obsolete rule of thumb. Instead of following a strict approach to investing, talk to an adviser about "how you can tailor your portfolio to your personal risk tolerance and goals."

Building an emergency fund
"Should I pay off my debt or save for emergencies first?" asked Anna Bahney at CNN. The best approach is generally to pay off the debt as fast as possible, especially when credit card interest rates are surging toward 20 percent. But life is rarely straightforward, and financial planners say that credit cards aren't "a safe fallback." So you should pay off your debt and save at the same time, "bit by bit." Begin by getting a handle on your fixed expenses. Whatever amount remains should determine just how much you can split between your debt and emergency fund. To really expedite the process, consider also taking on a second job or side gig until your debt is gone.