When diluting essential oils with carrier oil a good rule of thumb for the ratio of carrier oil to essential oil is to add 12 drops of essential oil to one fluid once of carrier oil.
This will give it the proper amount of dilution without being too diluted as to not work.
Good carrier oils to dilute essential oils with are Olive Oil and Coconut Oil.
Vegetable Oil can also be used as a carrier oil to dilute your essential oils.