You can develop a good voice these ways:
1. Desire it so much in your heart.
2. Pray and ask God for it.
3. Sing always with your mouth wide open and let every words of the lyrics come out of your mouth clearly.
4. Drink hot water or tea (not boiling).
5. Eat lots of real pure honey (test the honey by dropping some on the bare floor, if ants surround it then its not pure).
6. Drink raw egg always.
7. Avoid drinking cold chilled water.
8. Sing in your normal voice (tenor, treble or bass, etc).
9. Sing the solfa up about three of four levels.
10. Use recommended drugs that clears the lungs of toxins.
11. Watch other singers very well.
12. Systematically plan your singing practice.
13. Locate a good singing class in your locality.
14. Join a local church choir.
15. Join a yoga class.