(This first paragraph is mainly going to be for the females out there, but it may apply to some progressive and/or cross-dressing males as well.)
Remember your home economics classes where you were taught how to make a pie crust or sew a skirt? Well, maybe that was my class back in the day. I'm hoping that lessons are a little more practical these days. "Home economics" should include learning how to economically run your home, not only how to cook and sew. Both of these are useful things to know, mind you, and I believe everyone should know them, but I do believe understanding how to deal with daily living less expensively should be part of the lessons.
My days often include teaching myself lessons in home economics. For example, I can buy a bottle of pre-made cold tea to serve students in lessons (or myself when I want ice tea) for about 250-300 yen or I can make my own iced tea for 30-70 yen (depending on the type of tea). Making the cold tea myself requires adding water to a pan, boiling it, putting teabags in a jug, adding the water, allowing it to steep and cool, and removing the bags. In terms of my time and attention to the task, we're talking no more than 5 minutes of effort, though it is peppered across across a span of time in tiny fragments. In other words, if I buy that jug of tea, I'm essentially telling myself that it is worth paying a little more than 2400 yen an hour for someone else to make my tea for me (5 minutes is 1/12 of an hour so 12 x the difference between my tea and the cost of the bottle which would be about 200 yen).
Now, if you're one of those sorts who writes blog bits for $10 a post and can whip out one every ten minutes and calculate your time as being worth $60 an hour, then my advice isn't for you. Though, honestly, this whole "my time is worth $X per hour" when considering the value of pursuing a particular endeavor is a pretty big load anyway. It presumes that all effort is equal and that all time is potentially similarly productive or that there is sufficient demand for you work to keep you busy such that you can't spare 5 minutes to make your own tea without sacrificing a moment of precious earnings potential. Also, seriously, I'd rather work less and spend less than work more and earn more. The mental and physical toll of pushing myself to work for more cash is far less than making a pot of tea, but that's really just me.
If you start to do home economics in accord with your lifestyle, you can see where you're making choices to pay someone else to do the work for you and make an informed choice about whether the effort is worth it to you or not. I'm not advocating that people stop buying the things they want or enjoying their lives, but rather that they apply serious thought to their consumption and the real costs of it.
A lot of people find the sort of "nickel and dime" thinking I'm talking about petty and feel that it won't save you an appreciable amount of money. Whether this is true or not really depends on how much you feel you have to save to make it worth your while. When I was living in the U.S., there was a woman who worked at the same halfway house as I who my 22 year-old self used to scoff at because she'd do things like cut up old calendars to use for notepaper. I felt that she was saving the place a few cents and it was meaningless. Similarly, I used to get annoyed with my parents for insisting I turn off the lights all the time when I left the room. I thought they were being cheap and petty. Now, I'm cutting up my old calendars and turning off all the lights.
Since environmental concerns and energy consumption have been something I'm paying attention to more and more, I've found out that these small actions result in meaningful savings. Over the last year, I've discovered that taking showers by intermittently turning the water on and off has reduced my gas bill by about $15-20 a month in the warmer months. Having an air conditioner with low power settings and having two air conditioners (one in the bedroom and living room) and cooling only one room at a time has reduced summer air conditioning expenses by about $50-70 in the hottest and muggiest months.
Over the course of a year, I've discovered that just turning off the lights and television when I'm not using them and showering more efficiently has saved us more than $300 a year in living expenses and we sacrifice nothing in terms of quality of life. All it "costs" is developing new behavioral patterns. That's essentially the cost of a new iPod Touch or iPhone. And it is a real savings. I know what I used to pay and what I pay now. I've saved the bills and done the comparisons. It's not theoretical.
I never crunched the numbers specifically on what other habits we've employed to reduce expenses have allowed us to do because it can get pretty complicated. However, I do scrutinize the cost of home-cooked meals compared to eating out on a regular basis and consider the cost per portion based on the type of ingredients. I mainly do this to dissuade myself from going for convenience over effort as often as possible. For instance, I know making my own chicken pulao costs less than 150 yen per serving whereas going to an Indian restaurant will set me back at least 1000 yen (very likely more) per person. The serving sizes will be bigger, but they will also offer more food than I require and result in waste or overeating. Making chicken pulao also frees me up for the next two evenings as we'll eat leftovers for two additional days.
I know cooking is out of the question for some people as is carefully shopping for cheap food or buying in bulk (which also saves money). I'm not saying what people should or should not do, but rather saying that, if you want to save, you have to start considering the price of convenience. It's very likely more expensive than you realize.
(This is the last one, I promise. ;-) )