Print or write out the lyrics of a favorite song.
Speak through the song lyrics several times paying attention to how you are using your vocal cords to make each sound. Recognize how the resonation of the sound feels. The sound resonation should feel rich and full of tone, not airy.
Speak through the song lyrics again, this time noting how you are breathing in order to support your speech. You should notice there is no need to take big breaths or overwork the diaphragm in order to push out sound. Also notice that there is little movement in the upper chest and shoulders as you inhale.
Lastly, note how your body feels as you speak through the song lyrics. As you speak, you should be relaxed and have to do little physical movement to sound clear and smooth.
Alternate speaking, then singing one line of a song. Note any major differences in how the sound feels in your vocal cords. If there is a big difference, continue to alternate between speaking and singing that line to figure out what you are doing physically to change the tone. Make your singing tone as close to your speaking tone as possible.
Sing through more of your vocal range while practicing making your tone as similar in feel and sound as your speaking voice as you can.
Sing through the entire song with the same breath support you used while speaking. Do this until your breathing approach is as natural and comfortable as when speaking.
Now, sing with a body as relaxed as when you speak.