The classic dyad, caring about someone deeply and having them care about you, is a great way to do that.
But even if you’re unpartnered, or partnership isn’t your thing, the best parts of life are often when you’re caring for others.
After that, it’s more about knowing how you’re wired and doing whatever serves that. I need to spend a lot of time in physically beautiful places and experience novel sensations and adventures. Other people are homebodies.