When King George III descends into madness, court physicians attempt to cure him with torturous remedies while his dissolute son conspires to usurp the throne.

Thank you for posting your method, It's quite insightful. My only concern- I don't know who the protagonist is.
I like how this logline enables me to imagine the various forces driving the story; makes me want to know how it plays out.

The madness behind my method:? My initial logline was:

When King George III descends into madness, his dissolute son conspires to usurp the throne. (15 words) I focused on the rivalry between father and son.

But then I asked myself: is that really the story hook? Is that the "sizzle". I decided it that the "sizzle",? the really interesting "fun and games" feature (per Blake Snyder) was the gawdawful treatments the court physicians inflicted upon the monarch. Those measures now seem so primitive, so ludicrous, so inhumane, so, well "insane" -- but they constituted the state of the art of medicine in the late 18th century. (Modern conjectures are that King George III suffered from porphyria, a metabolic disorder.)

So I appended that story thread to the logline:

When King George III descends into madness, his dissolute son conspires to usurp the throne while court physicians attempt to cure the king with torturous remedies.

Then I revised it again putting the medical treatment in the middle of the plot because it does get more screen time than the dissolute son's court intrigues and, again, because it's the stronger story hook.

The madness behind my method:? My initial logline was:

When King George III descends into madness, his dissolute son conspires to usurp the throne. (15 words) I focused on the rivalry between father and son.

But then I asked myself: is that really the story hook? Is that the "sizzle". I decided it that the "sizzle",? the really interesting "fun and games" feature (per Blake Snyder) was the gawdawful treatments the court physicians inflicted upon the monarch. Those measures now seem so primitive, so ludicrous, so inhumane, so, well "insane" -- but they constituted the state of the art of medicine in the late 18th century. (Modern conjectures are that King George III suffered from porphyria, a metabolic disorder.)

So I appended that story thread to the logline:

When King George III descends into madness, his dissolute son conspires to usurp the throne while court physicians attempt to cure the king with torturous remedies.

Then I revised it again putting the medical treatment in the middle of the plot because it does get more screen time than the dissolute son's court intrigues and, again, because it's the stronger story hook.