this is actually a weekly ritual for me that I've been doing for like a year now. every weekend I block out at least 1 hour to just sit and 'waste time'. no screens, no music (these two are super important), just be outside and paying attention to the sounds and sights and smells. plus letting my mind wander. sometimes my wasting time is just a walk and taking film photos. or people watching. but the essence is you carve out a block of time to simply exist without any pressure to create or produce or do anything and to just do what you want. super grounding.
another thing I make time for is at least a one hour block to make something with my hands. can be press on nails, jewellery, clay, whatever. my brain struggles to be still and this is the only way I get the stream of thoughts to chill. also there is something so fulfilling about making something with your hands and seeing the product of your handiwork and toil (insert Dostoyevsky quote here).