Personally, what helps me is a cup of coffee, closing all tabs, Telegram, etc., and putting on something wordless in the background like lo-fi or just rain sounds.
If I’m playing live, it’s a bit of a different vibe (especially if I’m into the atmosphere). In that case, the less distraction, the better. The main thing is not reading the news or arguing with anyone before the game, so my head stays clear and no random thoughts creep in.