Much of it would be context/person dependent. Imagine they're "pretty good" on most traits and don't have any particular constraints. Health, relationships, money, all "pretty good".
What general methods, tools, approaches might you take?
Certain kinds of therapy, certain kinds of meditation, certain types of medication, certain types of coaching, certain activities, certain processes, and so on. Specific things, and/or meta things.
For constraints, imagine that you can spend 5 or 6 figures of US dollars per month, you're there in person full time with them. You don't know much about them, they don't have any notable medical conditions or past history. They're a mostly willing participant, but not entirely. You can try anything that exists as of May 2022.