My three favourite ways to ingest essential oils are:
The yummiest way is to use them in cooking. There are many oils that are suitable for cooking. I have written a list here. My friend uses rose essential oil in "rose dreams organic biscuits" in her organic cafe. They are delicious.
I have added essential oils to juices and especially Ning Xia Red Juice, tastes fantastic :) I also get an antioxidant boost!
I put the oils in an empty vegetable capsule and take them as needed. This is a good way if it is not a tasty oil or I need a good amount for illness etc.