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.
Get a credit card with no annual fee (preferably one with 1% cash back). Pay absolutely everything with card (only rent/mortgage, loan payments, and utilities should be paid in a different way, and that's only because they don't accept credit card). Pay it off in full once every month (the same date every month, and only once a month) before the due date so you never give the credit card company anything more than the actual cost of what you bought.
This makes it incredibly easy to track your finances. Rent/mortgage and loan payments are fixed. If you make a steady monthly wage you know exactly how much money you are getting every month and exactly how much you have left for all non-loan expenditures. That number should be at least $100 more than you pay to the credit card to pay off your past month of living every month.
When you bank more than usual in a month you feel awesome. When you have to pay more than you made in a month you realize immediately and can take quick steps to curtail it.
This also gives you real-world data as to what living costs, helping you to avoid the planning fallacy.
In the US, Mint.com can give you nice graphs of when and how you spend money, too.