Think about the things you use very often and/or for extended amounts of time. Buy the highest quality version of that that you can afford. For example shoes, chairs, beds, at any one time you will be in one of the three, so buy the best you can afford. Donating to a feel-good charity might also improve your happiness. The exact amount seems to be irrelevant.
Edit: Another possibility is to buy more than you actually need of items you use, like having multiple nail clippers at multiple locations for convenience instead of having to carry out one specific nailclipper.
Additional note: give yourself opportunity to make sure that “high quality” is actually “high utility”; I have failed to sleep well on some very expensive mattresses. Paying extra to buy from a company with a good return policy or trial periods is often worth it.
Think about the things you use very often and/or for extended amounts of time. Buy the highest quality version of that that you can afford. For example shoes, chairs, beds, at any one time you will be in one of the three, so buy the best you can afford. Donating to a feel-good charity might also improve your happiness. The exact amount seems to be irrelevant.
Edit: Another possibility is to buy more than you actually need of items you use, like having multiple nail clippers at multiple locations for convenience instead of having to carry out one specific nailclipper.
Additional note: give yourself opportunity to make sure that “high quality” is actually “high utility”; I have failed to sleep well on some very expensive mattresses. Paying extra to buy from a company with a good return policy or trial periods is often worth it.