In my opinion, what works best is when one style is represented through the theme or melody and the other is represented through the accompaniment (all the rhythm section).
To be able to adapt the voice in different genres, prepare the voice in order to get different collocations :)
Look for bands that already successfully created hits by merging genres. The first good documented example may be Aerosmith and Run D.M.C. with their hit "Walk this way". More recent example may be Korn and Skrillex with "Narcissistic Cannibal" and the band Linkin Park who changed/evolved/adapted their sound en genre with every album. Hope that helps somewhat. 🤘 🎶
Try to respect both styles and find similar or even opposite themes. As long as they compliment eachther. It should be synergy👍😊🎸🎶
Positive elements of both, mixed with subtle transitions and blend of styles