The rule of practice even applies here. As they say “Practice makes a man perfect”. What you have to do is regularly do practice. Make someone sit with you daily and make him listen to your sound. It is preferable that you sit with a person who has an expertise in the relevant field. Tell him to point out you loopholes.
If taking professional help is beyond your budget, then initially take the help of internet. You will find numerous websites as well as videos and even various softwares which can help you get started off. But ultimately you will need a professional coach.
It is important for you to determine on which range you are currently singing on. The wider that range you have the better the singer you will be. Versatility hence is the key over here as well.
While singing, make sure that you stand in such a position that you can breathe easily and because until or unless you can’t breathe properly, you won’t be able to sing and make your voice clear.
Do not forget, no matter where you are performing, for yourself or for an audience. Be confident and make sure you don’t panic. Initially, you might not get the acceptance and success you were hoping for but gradually as you will improve, things will get better.
Even while communicating normally, the way you speak your vowels is very important. Hence, make sure, regardless of the language you are speaking, that you practice your vowels because they will determine the understanding of your words by the audience. If you don’t speak your vowels correctly, people won’t understand you.
Last but not least, it is necessary for you to have achievable expectations. If you will practice less, don’t expect the outcome to be too much. But if you are regular in your practice, then be sure that you will see improvement in your voice over a period of time. Be patient.