He's most known for
His advice to writers is just totally awesome, and everyone should abide by it.
"You learn to write the same way you learn to play golf... You do it, and keep doing it until you get it right. A lot of people think something mystical happens to you, that maybe the muse kisses you on the ear. But writing isn't divinely inspired - it's hard work."
You just have to keep doing it over and over and over again until you get good. No shortcuts.
For more on the death of Tom Clancy see here.