I've been singing for years. Some of the keys to becoming a better singer include 1) practicing and stretching your breathing. Be sure you are breathing from your diaphragm or you will never have lasting power. 2). diction: it's hard to appreciate a singer you can't understand. 3). Technique: do you trill, belt, singsong, use twang, figure out a balance. Too much is obnoxious. Just enough flavors a song beautifully. 4). Find your voice. You don't need to sound like anyone else. Just be you. 5) practice in different timbres: if you belt, then try a breathy singsong approach. If you usually trail off a note try holding it out. It vice versa.