The great artists are the ones that can convey a lot with very little. Learning how to edit one’s self is one of the key core concepts of great game audio design—and, frankly, design in general. Too often, unskilled artists try to put too much into their audio design. But I can tell you from experience that working within self-imposed limits forces artists to be more creative and more decisive.
Listen to everything around you and memorize the sounds of the physical world. Always have a recorder and camera with you. Think about how and why things behave the way they do. And you better really like putting in long hours, because you're going to be putting in some really fucking long hours if you want to make sound and music for a living.