your EO ratio completely depends upon how strong your essential oils are...
try dipping a toothpick in each of d EOs and store them in a container, after sometime check the fragrance, if u feel any of the EO needs to be added just dip another toothpick in dat particular EO and drop in your container..
in this way you will be able to make out the ratio simply by counting the number of toothpicks for each EO..