My singing teacher started out as a voice therapist. He is still working with a lot of people with damaged voices that are there for therapeutic reasons as well as professional opera singers that there to level-up their game.
He says, the best thing you can do for your voice is to sing.
Singing will give you the proper "support" from your lungs and train the vocal muscles without wearing them out. One of the key aspects here is producing high quality vowels, and don't let the sound be disturbed by consonants. This is opposite to how the voice is used when speaking (in most languages), where consonants are of primary importance for people to understand what you are saying. However, consonants are interruptions in the air-flow and can easily wear the voice out and cause stain.