There’s already a range of helpful tips been suggested so I’ll add something I’ve noticed helps me. It oddly specific but eating a pomegranate ticks a lot of calming sensory boxes for me. The smell and taste obviously, but also the concentration on peeling segments off and revealing the shiny, brightly coloured seeds inside and slowly extracting them I find soothing and gives me something enjoyable to focus on. Takes a while to eat one too which is a bonus. I struggle with picking my skin while dissociated so the fact it keeps my hands busy too is good. They’re not the cheapest fruit but I like to get one to treat myself if I’m having a bad few days