In this case, they might be found inexpensively on Ebay.
I know exactly what shoes I like to wear to work, and I buy a couple pairs on Ebay whenever one of the colors (brown, blue, black) wears out. It's up to you, if you're willing to wear used shoes (you can also buy them new) but the pair I'm wearing look brand new and cost 1/20th the department store price.
I also buy identical pairs of socks in bulk. When they did stop selling the brand I liked, I got rid of all the old type knowing how much trouble it is to match different brands of the same colored socks.
I am lucky to have many pairs of identical socks which have their sizes written on the bottom side. Nobody sees the bottom sides of my socks, but it is so easy to look there when sorting them. So they don't get mixed with the older socks of the same color.
If in the future I don't have the same luck, maybe I could just make some marks on the bottom sides. For example one small colored dot, using a washing-resistant color. The most work would be finding that color. But marking the already sorted socks, that would be a question of a few seconds.
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.