I understand cleaning your face with oil feels counterintuitive. Trust me, I get it. Using oil is actually one of the most practical methods for cleaning the skin. To keep things as minimally-boring and non-text-book-like as possible, here’s the important fact: oil dissolves oil.
I've had success using a straight nourishing carrier oil, but tend to switch back and forth between a blend of castor and nourishing carrier oil and straight nourishing carrier oil.
Here are a few ratios for creating a blend: oily skin 50% castor oil/ 50% nourishing carrier oil, dry skin 25% castor oil/ 75% nourishing carrier oil, combo skin 30% castor oil/ 70% nourishing carrier oil.