Pay attention to what qualities work well for you. Next time you buy pants... consider yourself entering a "trial period" of, say, one month. Wear them a lot during that month.
At the end of the month: if they fit all the good qualities. and have no bad qualities... go buy another pair - you have now entered the second phase... which lasts, say, 3 months (time can be varied as you get more skilled at this).
At the end of the three months... if you've decided these pants are really awesome and comfy... you should still be within the same season in which the pants first came out - and can go buy another five pairs (or whatever makes you happy).
The idea being: after a month, if you put in a concerted effort to pay attention - you can probably tell whether a pair of pants will be perfect for you.... but if you're unsure - then buying just one extra means you have at least got two pairs of really good ones, but haven't spent too much extra if you suddenly find out that they fall apart on the dot at 2.5 months old. By the time you hit the longer period - you'll have worn them for a season and should have a very good idea of whether they fit really well (=1 to buying more), and whether they are wearing out unusually fast (-1 instead).
This is an extension of a comment I made that I can't find and also a request for examples. It seems plausible that, when giving advice, many people optimize for deepness or punchiness of the advice rather than for actual practical value. There may be good reasons to do this - e.g. advice that sounds deep or punchy might be more likely to be listened to - but as a corollary, there could be valuable advice that people generally don't give because it doesn't sound deep or punchy. Let's call this boring advice.
An example that's been discussed on LW several times is "make checklists." Checklists are great. We should totally make checklists. But "make checklists" is not a deep or punchy thing to say. Other examples include "google things" and "exercise."
I would like people to use this thread to post other examples of boring advice. If you can, provide evidence and/or a plausible argument that your boring advice actually is useful, but I would prefer that you err on the side of boring but not necessarily useful in the name of more thoroughly searching a plausibly under-searched part of advicespace.
Upvotes on advice posted in this thread should be based on your estimate of the usefulness of the advice; in particular, please do not vote up advice just because it sounds deep or punchy.