On your stovetop, place the dried rose petals in a large pot and cover with the filtered or distilled water. I put 2 cups in the recipe above, but you may need a little more or less... basically you want the rose petals completely covered in water, but not drowning in water (otherwise the rose water will be *too* watered down).
Over medium heat, bring the water to a simmer. DO NOT boil them.
Simmer the petals until the petals have lost their color.
Remove from heat and let water completely cool.
Using a mesh strainer, strain the rosewater into a glass jar, add in your 2-3 drops of Rose essential oil if you want, and seal!
I usually will put the rose water in a large mason jar and transfer to small glass spray bottles.
You can store it on your counter for 2-3 weeks or store in your fridge and it will last for a few months. I like to store the mason jar in the fridge and refill my small glass spray bottle every week or so.