No irony. No satire. No subterfuge or illusion.
Accept. That’s the first thing. Accept all conditions as they are, or seek within reason to change them, being mindful of the outcome on yourself and others. (The distinction is more arbitrary than you might imagine).
Avoid pre-judging persons, groups or situations. Many externals are not within our control. But our approach to our environment is. How many accidental and deadly rivalries throughout history were the result of hasty estimation? I’d imagine quite a few. Granted, others may not be sharing a similar outlook, but even so, you can still increase your happiness by not coloring your interactions with inaccurate or exaggerated mental projections.
Be vulnerable. This is tricky, as there’s there’s seemingly no way around the discomfort that vulnerability evokes. Still, it is an essential ingredient in being happy. It’s not just openness to information that keeps us healthy and sane, but also the raw exposure to experience, be it painful or blissful. When humans can achieve this profound honesty and openness together, it is truly magical.
Everything is temporary. Love hard, but know there is a time to let go. Work hard, but understand that your labor is not eternal. If you’re inclined to have accepted conditions as they are, attachment is less of an issue. If you have overly-identified your practiced self with the phenomenal world, then you will likely feel more pain. This is not religion; it’s fact. The hard part is trading a habitual mindset of grasping for one based in an healthy apprehension of impermanence. Love (re: compassion) helps.
Embrace new experiences. This is something anyone can do. The unknown seems frightening, but it can hold the key to many possible futures. Making informed choices is obviously wise, but being open to new things is a cornerstone to fulfillment. The surest path to unhappiness is a life closed off from experience. You don’t have to shoot the moon, but expand your vistas even a little bit, and benefit from the result.
Love as much as possible: people, places, things… yourself.