Most of thrift is about balancing what you need or want to buy with how much money you've got to spend. But there's an extra category: the things you neither need nor want to replace nor wished to buy in the first place, but that Society tells you you really ought to 'invest' in. Not making these purchases, They inform you, means that you are socially-inept, unhygienic, or just stingy to the point of ignoring your own needs. You might be OK using the same soap for your face and body, wearing the same dress to the office and a bar, and these are things no one would even know about if you didn't tell them, but if you did tell them, They would be horrified. Teenagers, who famously care what others think, are particularly susceptible to the You Need a New One message, but they're hardly alone.
So, some categories to watch out for:
Specialization: To an extent, this is something we're all guilty of. Using different products for shampoo and soap, say, or different outfits for formal and casual occasions. But there are degrees. This is particularly relevant when it comes to kitchen utensils. Anything designed just for a banana, a tomato, etc., can probably be skipped.
Replacements: It's clear enough why 'I needed a new one' is so often summoned as the reason for a purchase. It's not that you wanted a new pair of shoes, but that a particular pair wore out and needs replacement. (I, for one, cannot buy shoes without going through these motions.) But let's get real: not everything that wears out needs replacing, and not everything wears out when They say it does. A commenter here insisted recently that running shoes must be replaced after a certain number of miles and/or years. To me this sounded unnecessary, and I may not be as off as all that. Says one expert, a marathon winner and running-shoe salesman: "I know the shoe companies say 500 miles. I never go by things like that. I go by feel. When you’re on a run and you land on a rock and you feel it on your foot, when that happens you know your shoes have lost a lot of their cushioning or support and you might be wise to invest in another pair of shoes." Indeed. My running shoes are as hideous as can be, and are quite old, but until something changes perceptibly in the fit, no change is necessary.
Personal maintenance: As the recession lifestyle articles courageously reported, it is in fact possible to paint your own nails, rather than go to a salon. This did not surprise anyone other than women from Magical Lifestyle-Journalism Land. But forget about the lavish and the urban. Many basic expectations are, in fact, unnecessary. As MSI has investigated, a daily shampoo is at most a necessity according to season. And, a hint for those of us whose 'ethnic' hair is coarser and thus less societally-desirable than 'white' hair typically is - our hair takes forever to get greasy, so barring intense workouts or extreme heat, we can go the every-other-day (or, dare I say, every-two-day) route year-round. Yes, our hair gets interesting in the rain, but not having to shampoo every five minutes in order to avoid clumping at the scalp is a blessing indeed.
And, more generally, when it comes to beauty products, if you don't already use it, and 'it' isn't deodorant, toothpaste, or eyeliner, best not to start now.
Relaxation: Massages, yoga, days at the spa, months in the wilderness. I sympathize with the need to break up arduous tasks (like, say, returning 26 books to the library, from one's apartment in another borough, all in one go) with treats (say, iced coffee). But the notion that everyone These Days is just so stressed, that Life Today is so fast-paced that we all need to decompress, and that this decompression must manifest itself in ways more involved than parking one's self for a solid three hours in front of reality TV, has gotten out-of-hand. So while I don't advocate denying one's self the small indulgences that make life bearable, I think we'd all be wise to consider the restorative powers of staring at a wall or, failing that, a gossip website, before signing up for anything for which the promised de-stressing will be accompanied by a stress-inducing bill.
In other words, spending 'for others' has its place - going out with friends, gifts - but spending on yourself should not, with some obvious exceptions, take Society into account.