Non-Violent Communication ("NVC") by Marshall Rosenberg changed how I communicate forever. The big lesson to focus on people's underlying needs in a conversation = gamechanger.
Weigh the ROI of changing your environment vs changing yourself
A lot of people on HN are do-it-yourself, bootstrap types. So you'll naturally get "why don't you just do XYZ."
There's merit in that, but sometimes changing the environment is more effective. That environment may be literal physical location (closer to friends or activities you're interested in), a job environment (different industry) or, at a smaller scale, your home environment. I finally started updating my place and having friends over and it's made a huge difference.
On a personal note: a hard lesson I had to learn for myself is that having fun (as weird as it sounds) is my responsibility. I found that I tended to look "outwards" for stimulation, fun, validation...waiting for the world to give me things.
Hanging out with people who were great at cultivating their own fun & energy helped me realize 1) this is something I could cultivate and 2) I was shirking responsibility.
IMO this cultivation of one's own energy is a long, internal journey. But worth it.
Many responses here don't address OP's question about day-to-day practices.
My spiritual practice: meditation, journaling, breathwork. Occasionally, psychedelics with close friends in nature, which often starts out with a prompt regarding with we want to get out of the experience