This post is from staff writer Sierra Black. Sierra writes about frugality, sustainable living, and getting her kids to eat kale at Childwild.com.

When I started getting serious about frugal living, my husband dredged up one piece of juicy financial advice he recalled from his grad school days: Use half of what you normally would. He was talking about consumable goods like shampoo and dish soap. The idea is to reduce by half the amount of these things you use by doling out smaller portions. Normally use a quarter-size dollop of shampoo? Try cutting back to a dime.

There’s no need to stop at half, actually. You can keep scaling back your usage gradually until you hit a point where you actually don’t have enough, and then creep back up to the last place it felt good. Maybe that dime-size drop of shampoo isn’t enough for your hair, but a nickel-size portion gets the job done nicely.

This approach works. I bought a large container of dish soap at Costco in March of 2009 and have not run out yet. This is not for lack of doing dishes: There are five people in my household, and we do all of our cooking from scratch. We make a lot of dirty dishes, and we wash a few sinkfuls a day.

One reason cutting back on consumption has worked so well for me is that I automated it. Rather than depend on my fragile mind to remember to use smaller sloshes of soap or shampoo every time I wash, I buy my cleaning products and personal care items in bulk and pour them into smaller containers — at half strength. The small plastic bottle next to the kitchen sink contains half water and half soap. I use the same amount when I wash the dishes, but I’m going through the soap at half the rate I used to.

The 50-percent solution has worked so well for me with my household goods, I decided to expand it to other areas of my life. In addition to basic consumables, I’ve applied to 50-percent solution to:

  • Shopping for clothes. I mostly don’t shop for clothes, but on the rare occasion that I do, I’ve learned to ask: Do I need two of these? I picked up the habit of buying multiples of something I like when I was younger. While that often works out well, just as often I can get by with one pair of jeans or one new bra.
  • Going out to bars and restaurants. This is often a trouble spot for me, since I love going out with friends. Scaling back that type of social activity by half lets me stay close to the people I care about without busting my budget.
  • Over the counter medications. Take two aspirin and call me when you’ve tried cutting back to see if one will do the trick. I wouldn’t suggest trying this with your prescription meds, but for simple over-the-counter stuff like headache medicine, I’ve found that a half dose is often perfectly effective.
  • Groceries. My kids will eat a near infinite amount of fresh fruit, pretzels, and yogurt. How much is enough? The only way to tell was to gradually buy less until we ran out and they complained. We’ve cut our grocery budget in half combining this with other grocery savings hacks. We also waste practically no food these days, which is a pretty great feeling.
  • Therapeutic appointments. My husband sees a chiropractor regularly for chronic back issues. Over time, they’ve gradually scaled back their appointments from twice a week to only twice a month. This saves us time and money. As with all these measures though, the key is to get to Enough. Cutting back too much on these appointments would cause him pain and interfere with his life. The balancing act is to be sure he gets what he needs from his chiropractor, without over-committing resources that could be better used elsewhere.

Basically, we’ve tried tapering off anything I routinely spend money on where I have some control over the amount I use. For example, cutting dinner dates with my husband down from once a week to once a month felt too scarce, but every other week is a good balance between staying frugal and staying connected.

In general, this approach saves me money. In a few cases, it’s prompted me to spend more. I wasn’t spending enough time with my husband, for example. As our financial situation has stabilized, that’s a problem I’ve started throwing more money at, taking us out for “date nights” a few times a month instead of insisting that we always stay in. Yes, eating out is expensive. But the time alone together away from the weight of housework and unfinished tasks at home is priceless.

As with any money hack, the most important thing isn’t how I save the money, it’s what I do with it. A dollar saved is only really saved if I don’t immediately spend it on something else.  The savings from these gradual reductions in consumption are often harder to see than the clear figures one gets from canceling a subscription and saving the monthly fee.

How much have I saved on laundry soap over the past year? It’s possible to track that data and get a real answer, but I don’t keep records that detailed. The dollars I’ve saved didn’t get banked straight into my savings account. Instead, they’ve padded my margin a bit, making it easier to stick to our budget each week and possible to splurge on treats like dinners out with my husband.

Even beyond the actual money saved, I get a psychological benefit from doing this. Like my commitment to buy nothing new or my 30-day list, the 50-percent solution acts as a checkpoint for purchases. Do I really need this? Do I need all of this? Could I make do with less?

Being in the habit of asking myself those questions has saved me a lot more money than just cutting my shampoo with water does. It helps me stay in a frugal mindset when I’m shopping. That’s not easy to do. Stores are designed to push you towards impulse buys, and being armed with mental money hacks helps me fight back against their subtle (and not so subtle) marketing.

I love this approach because it helps me find balance. It’s not about committing to a life of extreme austerity, it’s about avoiding waste. I often think of the curve at the beginning of Your Money or Your Life that shows a person’s happiness increasing as they have the resources to supply their basic needs, and then some comforts and finally a few luxuries. Beyond that magic point of Enough, the curve calls off as more and more luxuries are piled on but fail to satisfy.

The 50-percent solution helps me know what my personal Enough is. What’s Enough soap? Enough entertainment? Enough snack food?

Scaling back incrementally lets me find those magic points on the curve and stay close to them. I get to have Enough to be happy, without wasting resources like money, time and energy on acquiring more of something than I need or want.

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This article is about Budgeting, Money Hacks