This may be a very tone deaf thing to say, but what really helps me is to just tell myself I am happy. It's certainly not fool-proof when faced with genuine problems, but I often find myself unhappy or annoyed for no particular reason. In those moments I just tell myself I have everything I need and life is great, and then it just feels better.
That said all the findings that these studies seem to gravitate towards like close relationships also align with my experiences as being powerful effectors.
that doesn't feel tone deaf to me, and is a legit strategy to kick-start deeper happiness and satisfaction. I a huge component of money-related unhappiness to me appears to be context, i.e. people who need more.
I feel like it's directionally like telling depressed people to just "stop being depressed". Works for me because of where I'm at currently but idk how generalizable it is.