No screaming and yelling. A single scream has the possibility to damage your vocal folds.
Drink enough water, non-caffeinated, or non-alcoholic drinks.
Manage reflux and consult with your Doctor.
Do not smoke and vape and limit exposure to second hand smoke.
Use amplification in large spaces.
Use one earplug in noisy settings so you can hear your voice better and you don’t push to be heard over the noise.
Consider using a humidiflyer if you find air circulation on airplanes dries out your vocal folds.
Learn good vocal techniques to increase long-term strength and voice performance.
Be aware of the voice side effects of medication you may be taking. Discuss with your Doctor if there are other options if side effects are of concern. The National Centre for Voice and Speech has a searchable database of the possible voice side effects of medication.