Let me see...
Take a moment to identify one positive event each day.
Okay, not difficult. I even feel happy when I fold my laundry tidily.
Tell someone about the positive event or share it on social media.
Nope. This is really a bad idea. Because 'someone' can ruin your positive feeling and you get addicted to social media. Your emotions will be like riding a roller coaster. You start watching how many 'like' or 'dislike' you get a day.
Start a daily gratitude journal...
Great. Because I do feel good whenever I drink a nice cup of something.
Identify a personal strength and reflect on how you've used this strength today...
Dunno how to practise it. Not that smart.
Set a daily goal and track your progress.
Umm, good, but not daily. It's twice a week trying to speak anything I feel (even I feel stupid) in Marianne's session and try not to humor her, because it's a bad habit when you live in Japan.
Try to practice "positive reappraisal".
Not difficult until someone interrupts it.
Do something nice for someone else each day.
Not sure. Because your meat can be someone's poison. In other words, if that person doesn't expect your kindness, everything will just turn out ugly.
Practice mindfulness by paying attention to the present moment.
Fine. I'll try.
Thank you @mheredge