First step required that you bring out the worst. Scream as loud as you can. Test your highest vocal points. Always know how bad you can sing.
Step2
Now check your breathing and stamina. get control over your breathing. see how you can sing while inhaling and how good you are singing at exhaling.
Step3
now sing with different vocal. find out your best vocals. you would be suprise to see every on can sing as good as the best. you just have to search for the sound. and it is the Sound of the music.Search it