Mostly it was sentimental stuff, I know we shipped cutlery, paintings, a very small number of books, clothing etc. But roughly speaking we'd got rid of anything and everything we could easily replace.
(And it has to be said that the pair of us carried a few suitcases for our flights, we'd filled those with plants and other fragile items.)
Nothing too exotic, just things like spider-plants and some indoor vines. She'd lightly-wrap them with newspaper and then stick them in the middle of her suitcase surrounded by clothes.
So pretty much all the plants we took from Scotland to Finland were ones she'd already moved in the opposite direction a year or two earlier!
I know some countries have restrictions on plants/animals and similar things, but it never seemed to be a concern for her travels.
Don't do that if you visit Australia. They'll (for real) throw you in jail if you bring in plants or animals without a permit. ;)
https://www.agriculture.gov.au/import/goods/plant-products/h...