A suitable recording of your Vocal:

A clean and clear recording of your vocal, with no background noise.

Try also to eliminate any "pops" when pronouncing "P's" and any other microphone noises,

such as handling noise or wind noise.

The better and clearer you can record your vocal - the better it will sound on the final mix.

Clear vocals recorded from a good Mobile Phone can be quite acceptable, but do avoid distortion or overloading.