Pick words that describe how you naturally talk to friends, not aspirational corporate words. If you wouldn't say it out loud in conversation, it's the wrong adjective.
The core adjectives should stay the same everywhere, but the intensity can flex — slightly more polished on LinkedIn, slightly more playful on TikTok, same underlying personality.
Studying admired brands helps you notice structural choices (pacing, openers, humor style) you can adapt in your own words, without duplicating their actual voice.