do it right the first time, every time

Michelangelo was working on a statue for several days and he was taking a long time to retouch every small detail which seemed rather insignificant to a bystander. When asked why he did it, Michelangelo replied, "Trifles make perfection and perfection is no trifle."
Most people forget how fast you did a job, but they remember how well it was done.

If a man is called to be street sweeper, he should sweep streets
even as Michelangelo painted, or Beethoven composed music,
or Shakespeare wrote poetry. He should sweep streets so well
that all the hosts of heaven and earth will pause to say, here
lived a great street sweeper who did his job well.

--Martin Luger King, Jr.