I do not have sensitive skin so do not dilute my oils..though the "hot" ones like oregano, thieves, wintergreen I will dilute. I think diluting depends on the person and the oil and the quality of the oils being used. When I dilute I use a 50/50 ratio. I always recommend doing a skin test to see if you are sensitive to it and need to dilute the oil. Take one drop of oil on the wrist..if you have a burning sensation wash with soap and dilute the oil.