How to sublimate sexyal energy?

To sublimate is to make something "sublime", to refine an energy by augmenting its vibration so the frequency rises. The lowest frequencies are in Muladhara chakra and the energies become more refined until we reach Sahasrara, the crown center at the top of the head. (See the category about Chakras). 

To give some examples: Sexual energy can be refined to mental energy which is practical if you are studying for an exam. The sexual energy can also be sublimated to the heart level (Anahata Chakra) where it will manifest as a feeling of love, or it can be sublimated to the level of Vishuddha Chakra where it can manifest as artistic inspiration.

In the case of many people the energy has a tendency to run downwards and will be felt as states of lazyness, tiredness and missing inspiration. The descending energy stream must be turned around so that the energy (SHAKTI) reaches the top of the head, Sahasrara, where it can unify with the consciousness (SHIVA) and create the highest state of bliss.

How does one sublimate and transmutate?
Transmutation happens automatically by practising sexual continence. The sexual secretions are reabsorbed into the body and transformed into energy. This energy will stay at the level of Svadistana Chakra (at the level of the sexual organs) and can begin to stagnate. One can feel this as a tense feeling in the area and emotionally we feel irritable and frustrated. Pre menstrual tension is an example of energy collecting at the level of Svadhistana Chakra before the onset of menstruation. The solution to this physical and psychic tension is to circulate the energies through sublimation. This can be done through the practice of yoga postions (called asanas) on each of the 7 chakras.

Another way to sublimate is through mental concentration. When we need to sublimate, either during or after the lovemaking, the energy is visualised as a wave of warmth that rises up to the level of Ajna chakra in the middle of the forehead. It can be felt as shivers running up the spine. The power of focus is a very powerful way of moving energy. Wherever you focus during lovemaking will send the energy in the direction of that focus. If you focus on Anahata Chakra the sexual energy will be lead to the level of the heart and you will feel an intense state of love. 
Yet another way of rising the energy is by taking herbs as is prescribed in the Indian science of Ayur Veda. Herbs are best taken by placing them under the toungue for prolonged periods so that your structure will enter into a process of resonance with the beneficial resonances of the herbs. 

Meditation sitting in the lotus is also a powerful means of sublimating the energy. The folding of the legs will lock the legs and make the spine very straight giving a very strong sublimation. 

If everything else fails, jogging or taking a long walk can also help as it distributes the energies to Muladhara and Manipura Chakra, but it is not as elevated as the other forms of sublimation as they more directly channel the energies to the higher chakras (Anahata, vishuddha, Ajna and Sahasrara).