By first understanding the science of sound; not spending exorbitant amounts of money on boutique power cords, speaker wire, amps, etc., that don't actually change the sound AT ALL but feed into snake oil marketing that is killing this hobby. Then splurging on things that actually matter, like speakers, by listening to as many different brands/models as possible to see what sounds good to my ears.
There are so many speakers, that's the hard part.