You can always offer them energy. There are a couple of ways that you can do this. You can breath in energy and then exhale it and focus it into a ball in front of you. You can then vibrate runes into the ball to empower it, or direct energy from an orgasm into it. You can also just create a ball from orgasmic energy and offer that. If you lack the visualization skills to direct the energy into a ball at the moment then you can simply ask the demon/demoness to take the energy from you. The best time to offer energy is when you have an energy buzz going. Offering energy can be done at any time and any place. If there isn't a certain demon that you are close to or working with, then you can always ask Father Satan or Mother Lilith to take the energy. I hope this helps some. =)