well the only thing you need to do, is basically coping your mono track and pan it on one side, the original on the other side. Then you pitch shift one of the tracks by a couple of cents and voila! The only thing you need to remember, when you sum back everything in mono, it can sound phasy. So the better trick is to do this:
- Make 2 copies of your original
- Pan these copies L and R
- Low Cut them up to 2kHz or more
- Pitch the L side by -5 cents and the R side by +7 cents.
- Sum these track to one stereo-track back and dial in back to your original mono-track.
- Now you still have your untouched original, but have spread out the higher frequencies, where you hear the phasing less!
- If you are super passionate, you can use Melodyne and experiment with the processed vocals by moving them more to the grid or out of sync. The end result is like you have 3 different takes!
Best regards and take care,