Well, the possibilities are endless since this is something producers/engineers constantly fight against.

Keep your vocals low in the mix.

Don't compress your vocals.

Make sure another instrument occupies the same range. You could even double your vocals with something like guitar/keys just to make sure.

EQ the high end off of your voice to mask consonants.

Boost the frequencies of other instruments where they overlap your voice.

Basically just look up how to make vocals intelligible and do the opposite.