One thing I've always found satisfying is a complete restructuring of my library. The move to the new house afforded me the opportunity to do that. Groups of books that started with only a handful that in the meantime grew to a shelf can be collected together, etc. How your books are organized is both influenced by and influences how your thoughts are organized.
My go-to bookshelf, to the left of my desk, has some important categories that used to be scattered across several shelves:
My history of economic thought shelf has now been divide between two shelves: a shelf shared by Cambridge (Marhsall, Pigou, Keynes, Robinson) and Austrian thought, and a shelf entirely dedicated to the history of American economic thought. My American economic thought was previously scattered but I think it's good to have it together. Also on this bookshelf is a shelf dedicated to my economics of science and engineering books. Above that is a shelf dedicated to labor economics. Above that is a shelf entirely dedicate to the interwar economy, with books on the Versailles conference on one side, running through 1920-21, the twenties, and the depression on the other side. Above that is the non-labor, non-historical economics.
The other bookshelf in the room is entirely dedicated to American history. The most important shelf on that bookshelf is dedicated to local (i.e. - Maryland and Virginia) history in the mid-twentieth century. About half of that is taken up with books on the Maryland Constitutional Convention of 1967-68, and the other half has a mix of Virginia and Maryland material and some Civil Rights movement material. Jefferson and Washington share a shelf. Colonial and revolutionary history have another shelf. American economic history has another shelf. There is about half a shelf dedicated to Marxism and socialist thought at the bottom.
The third bookshelf in my study has a shelf of philosophy at the top, a shelf of random social science (some political science here) under that, and the other four shelves on that bookshelf are taken up with twentieth century history up through current events (mostly international, with lots on energy). These four shelves do something I've been wanting to do for a long time: integrate my library with Kate's library, which has been separate for awhile. That means there's a ton of twentieth century Russian history. But the point is, it's ours now - not mine and hers. That's good I think.
She used to have a lot of Russian literature mixed in with her Russian history. That's purged. All fiction is in the bedroom. Almost no fiction is in the study (I make exceptions for Lovecraft, Melville, Fitzgerald, and a few others that seem to fit well with the American history shelves).
Travel books, cookbooks, and (temporarily) my half dozen accordion folders with printed articles are in the second bedroom.
And now, I'm going to make bacon and pancakes to fuel us for a day of painting.