I also like to work on talking before the bird is uncovered in the morning. They are quiet and receptive at this time. Start with a one-syllable word. Once your bird repeats that first word, she will quickly add more. The more variation you use in tone and inflection, the more she will like the word or phrase.
Many birds seem to prefer the higher-pitched voice of women and children.
Even though you might feel silly, get dramatic when you are repeating lessons. A monotonous repetition of a word or phrase can be done with a tape player and usually is not very effective. Act silly and use creative voices and you will be right on the bird's intellectual level, which is thought to be that of a human toddler. Make up a little song using the word or phrase that you are trying to teach. Often they learn phrases that you set to music as regular speech without the tune, but they do sing entire songs.