The three that matter
Sound. A solid-core door and insulation in the partition walls do more than anything else, and both are cheap while the room is open.
Light. A window behind you blows out a camera; a window facing you is ideal. Layered lighting rather than one ceiling fixture.
Power and data. Enough outlets in the right places and a hard-wired network drop. Wi-Fi across a block wall is worse than people expect.
What a home office conversion needs that a bedroom does not
Acoustic separation and enough power in the right places. A solid-core door and insulation in the partition do more for a working room than any amount of furniture, and both are cheap while the room is open. A hard-wired network drop matters more than people expect, because Wi-Fi through a concrete block wall performs far worse than through a stud partition.
Florida particular
A converted garage or a room over one runs hot. Check the air handler can actually serve it before assuming a vent is enough, because an office at 80 degrees does not get used.