If I was calling the moves. For a short simple answer.
After Iwo Jima and Okinawa minimize landings and land fighting.
Blockade - and keep tightening that noose. Everything from row boats on up gets blasted. Sailing or not.
Bomb and strafe anything but Palace and hospitals. Delayed detonation bombs hamper repair efforts.
Napalm crops, livestock, same for forests in dry season.
As bombers and fighters from ETO arrive, the intensity increases and defenses decrease.
Battleships, cruisers, destroyers blast all that they can reach. PT boats, PGMs and such land sabatoge parties.
Masatake Okumiya and Jiro Horikoshi in the 1950's wrote about defenses and economic/industrial activity crumbling as was in 1945.
Also, industry took a big hit from the 1944 earthquake.