A good upstanding life is a subjective matter that will need to find some grounding to deconstruct on the philosophical plane.

One option is to consider the perennial competition between collective success vs individual gratification, among human societies, which lays the basis of a lot of ethical direction.

A human is like a crazy efficient optimization machine that encodes not just its own learnings but also experiences gathered over many many generations. Some injunction of nature vs nurture is implied here, which I'll keep myself from getting into.

Anyways, so an individual needs to optimise both for self (the short-term) and also for the society (the long-term). At the same time, each one of us is traded cards we can play with.

One of the best strategies that can be employed to attain a fruitful and fulfilling life is the one that lets you use your cards to the maximum positive effect.

A number of traditional philosophies seem to offer a solution in mindfulness, self awareness and acceptance as a means to move forward efficiently. What this means is that, one lets oneself be directed by a balance of thought and action, that avoids you from becoming too reliant on your egoistical motives. This seems like a rather difficult thing to explain in a few words, so I'll leave it there for you to explore further if you find it interesting enough.