Writing stuff down is invaluable. The sooner after comedown, the better. Even better: jot down a line or two while you're actually still tripping (recording devices work well too)- sometimes you'll have a Eureka moment and are able to condense some important understanding into words- it can be tough to operate a pencil from that height but especially with the slower psychedelics, is fully possible. (I even have a very particular style of handwriting that I produce in that state.)
If you paint or draw or sculpt or play a musical instrument, doing your creative thing right after a trip can take inspiration from the experience and express it in the physical world. It doesn't have to be technically refined- just honest.
Long walks are great too.