Mary Hunt lists a simple trick to stop spending as follows:
Get into the habit of quickly calculating the annualized cost of things and you’ll achieve an effective way to get mindless spending under control.
So if you spend $20 a week on an item (coffee, soda, etc.), realize that those purchases are costing you $1,040 a year. When looked at from that perspective, maybe you think the costs are worth it and maybe you don't. Her take is that once you see how much some things cost over the course of the year, you'll decide that they aren't worth it and stop spending on them.
Case in point: eating out at lunch. If it costs you $10 a day to eat out, that's $2,500 a year (five days a week, 50 weeks, $10 a day). Obviously you can bring your lunch for much less than $10 a day, so there is significant savings to be had by simply changing your habits a bit.
Does anyone do this? I do (in addition to doing the "hours of work to pay for something" calculation) to see if something is really that costly. For instance, our cable TV costs us $19 a month or $228 per year. Is it worth it? It is to me since it is less than what we'd probably spend on other forms of entertainment if we didn't have it. Besides, it doesn't take me long to earn $228, so the work/cost ratio is good.
How about you? Do you look at annual costs when considering your spending?