The Leak: Letting the water run.

The Fix: Turn off the tap while you’re brushing your teeth or shaving—every minute the water flows wastes up to 2 1/2 gallons, according to the Environmental Protection Agency. Run full loads in washing machines and dishwashers. Water plants in the early morning to ensure that the water goes into the ground instead of evaporating. And use a bucket to wash the car, hosing it off for a quick rinse, to save 90 gallons of water per wash. For more conservation tips, go to the California Urban Water Conservation Council site, at h2ouse.org.

The Leak: Keeping six months’ worth of salary in a savings account as an emergency fund.

The Fix: Littleton, Colorado–based financial planner Sal Miceli advises clients to sock away two months’ salary into a savings account and invest the rest. Otherwise, you lose out on the interest that extra four months’ salary could be earning in a CD or a money-market fund, or you’re wasting money paying finance charges on credit-card balances you could be whittling down. For an unexpected expenditure, a home-equity line of credit, which usually costs nothing until you use it, can be tapped in an emergency.

The Leak: Not taking advantage of flexible-spending accounts.

The Fix: Employers offer flexible-spending accounts that let you sock away up to $5,000 per household tax-free for medical expenses, which you can use for health-insurance copayments, prescription drugs, eyeglasses, contact lenses, and even nonprescription drugs, such as aspirin. Estimate your needs carefully when open enrollment comes along. The IRS now offers a grace period of an extra 2 1/2 months to spend the money, so you don’t have to rush to spend it all by the end of the calendar year. You can also set up transportation-reimbursement accounts to save money on parking fees and bus and train fares—$2,640 for parking or $1,380 for transit. Just save your receipts and fax or mail them in with the required form and you’ll get a check in the mail or have the reimbursement deposited into your bank account.

The Leak: Bounced checks.

The Fix: Sign up for overdraft protection and link a savings account, credit card, or line of credit to your checking account. Almost all banks offer this service for free or for a nominal annual fee, and they typically charge a fee per transfer. You’re responsible only for paying the interest on any credit you use, and you can avoid that by using the money in your savings account as your backup.