Personal financeMoney a little tight? The secret to getting the cash coming in to exceed the cash going out is to reduce your spending. It’s as simple — and as tough — as that.

But once you understand that cutting expenses is really like giving yourself a tax-free raise, the job gets much easier. The challenge is to find realistic yet painless ways to trim spending without taking all of the fun out of your life.

Go on a cash diet. It’s best to spend only cash in order to curb mindless spending. Surveys indicate that cash customers are more mindful of what they’re doing, and therefore spend 17 to 23 percent less than those who pay with plastic.

Also, limit ATM trips to once a week. Develop an envelope system for areas that can get out of control, such as office lunches and entertainment. Take your ATM cash and distribute it among your marked envelopes. When you go to lunch or a movie, take the money from the corresponding envelope. When the money is gone, that means no more spending until the next fill-up.

Tip: A $100 bill stashed in your wallet will give you an uncanny sense of security and willingness to leave the plastic and checkbook at home. Equally remarkable, you will be reluctant to break it to buy a cup of coffee or new lipstick.

Slash the cost of hot water. Twenty percent of your utility bills may be attributed to the water heater, which does nothing but keep about 40 gallons of water very hot, day in and day out. Keep the water temperature on low or 120 F (the highest temperature recommended for a household with children or the elderly, and the lowest temperature recommended for washing clothes) or to a temperature that is comfortable for your needs. Check the instructions on the water heater for exactly how to do this.

Tip: For every 10 F you lower the temperature, you will save about 10 percent of your water-heating costs — a considerable savings over the course of a year. Save even more by buying a $35 electric water-heater timer, available at most home improvement centers. The timer — which you can install in less than an hour — lets you set specific on and off times that suit your lifestyle so the water is hot when you need it.

Stop Shopping. Unless you have a specific need for something in particular and the money to pay for it, don’t wander aimlessly through the mall or surf the Internet to see what looks good. Instead, plan purchases, and then find the best value for what you need. Remember, you rarely discover a true need while in a store.

Tip: As you identify a need, write it on your “To Buy” list for your next planned purchasing trip.