im not trying to be flippant
but
start with the best roast you can find.
and the best is what you roast at home.
get it on the dark side
and make real espresso : extract at 9 bar.
use that and use more finely ground coffee than you might for a perfect espresso.
baring that
find a place near you that makes the Real Deal Espresso.
that won't be Starbucks , nor Peets.
extracting at 9 bar @ 205 F is very different that at 1 bar @ 212
or however hot you milk/cream gets.