You may want to have special oils and accessories available for the occasion. Make sure you have everything you need for safe sex. Be certain any lube you use is compatible with any condoms or diaphragms you may be using. Sacralizing sex doesn't reduce your chance to receive a STD. Take responsibility for your sexual health and do what is necessary to be able to enjoy yourself without fear. If you are not certain of your partner's state of sexual health then you may want to re-evaluate whether practicing sacred sex is a good idea at this stage of your relationship.
Sacred sex should not be a rushed affair. Spend lavish time on caresses and kisses. Recognize you are interacting with your partner's spirit as well as their body. Engage all of your senses. Appreciate the unique taste, smell, feel, sight, and sound of your lover. It may help to imagine yourselves as deities who were lovers -- Inanna and Dumuzi, Zeus and Ganymede, or Artemis and Callisto as represented in modern Dianic myth. Perhaps you may take the roles of the Lord and Lady of the Wiccan Great Rite, and the love and devotion you feel for your partner may become magnified by the love you bear your Gods.
Pagans, Ancient and Modern, revere sex as a holy part of life. That does not mean we consider it a purely religious act. Just as we may take cakes and wine in ritual, we do not have quite the same feeling of sacrament over a bowl of Cheerios. Mundane is sex is not less than sacred sex, just different.
Sacralizing sex is experiencing love through mythic eyes. We become caught up so easily in paying bills, doing dishes, and running errands that we sometimes forget how extraordinary our lovers are. See your lover through new eyes, holy and perfect. Remember the Song of Solomon: "Thou art all fair, my love; there is no spot in thee."