How to use inner feeling (intuitive feeling) while taking refuge

Starting ngondro practice, taking refuge in 3 jewels. As we know most of the Tibetan schools use the pretty common attitude. So if we are not talking about the differences, but the inner feeling and its development during each stage of the practice. What are they? Could somebody experienced walk us through it or refer to relevant text? Please try to avoid general answer - there is already plenty information in the literature. This question is about the essential experience which I consider as the key of the successful practice. Thanks in advance.