Many vocal exercises can give you great benefit, the questions that you need to answer before asking this question is:
HOW do you currently sing? Do you sing soft and high? Loud and low? All of the above? Is singing comfortable as it is now? Etc.
WHAT do you want to sing? What you do for death-metal singing is very, very different from what you do to make the sounds in classical singing, even though both can be sung in a healthy way. So having an idea what you currently sing and what you want to sing becomes essential down the road.
There is an incredible amount of diversity in what one can do with one’s voice. As a result, people’s default speaking and singing will land within a wide spectrum.
Everyone has different vocal habits, so one exercise that might change a person’s vocal abilities in a profound and lasting way may do next to nothing for another person.
We tend to not notice our vocal habits, this is why feedback from a voice teacher, high-quality recording device, or outside listener is needed more often than not.
Once we know how we sing and what we want to sing, then the next question is:
What kind of exercises do I need to sing like (insert genre here) and how will I know when I have found the sound?
Exercises are there to either help you discover, or remember a vocal coordination that you want to make a particular vocal sound in a healthy way.
The question after that for most genres then becomes: