Patience, listen, research, learn. This is a long term pursuit that can be incredibly rewarding. However you have to be comfortable with ambiguity and learn to listen and hear. Each turn can be rewarding. Early days are the hardest until you get the basics down: not believing marketing hype, measurements, and in "Giant Killers". Sound quality comes in different flavors... highly detailed, punchy, natural and musical. The later is likely to be the most satisfying long term... but lots of folks like sound spectacular system. Figure out what you like... but realize it will change over time.
Not one thing, and only a tiny sliver.