The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) writes (listen to audio recording for precise citation) that on Friday night, after one looks into the Kiddush cup and recites the introductory "Le’shem Yihud" prayer, he should begin reciting the actual Kiddush text. The custom in our community is to begin Kiddush from the words, "Yom Ha’shishi." After completing that paragraph, and before reciting the Beracha of "Boreh Peri Ha’gefen," one should recite, "Sabri Maranan" (literally, "With permission, gentlemen"). The Ben Ish Hai writes that even if one recites Kiddush alone, he should nevertheless recite, "Sabri Maranan" for reasons related to Kabbalistic teaching. After reciting "Sabri Maranan" and the Beracha of "Boreh Peri Ha’gefen," one recites the Beracha of Kiddush, which contains precisely thirty-five words.
The Ben Ish Hai writes that one should recite the Friday night Kiddush while standing, in accordance with Kabbalistic teaching. Before drinking the wine, however, one should sit and then drink in a seated position. The Ben Ish Hai notes that Rav Haim Vital (1543-1620) recorded that this was the custom of his teacher, the Arizal (Rav Yishak Luria, 1534-1572). The reason for sitting while drinking Kiddush, the Ben Ish Hai explains, relates not to Kabbalistic teaching, but rather to simple "Derech Eretz" (manners and etiquette), as it is appropriate to sit while drinking. In fact, the Gemara in Masechet Gittin (70) lists three habits that endanger a person’s health, and includes drinking while standing in this list. Interestingly enough, the Ben Ish Hai observed that the Rambam (Rabbi Moshe Maimonides, Spain-Egypt, 1135-1204) omitted this warning from his Hilchot De’ot, where he discusses proper health habits. The Ben Ish Hai speculates that the Rambam perhaps understood the Gemara’s comment as noting the danger of engaging in all three activities listed, but not of each independently. The Rambam thus concluded that there is no danger involved in drinking while standing, and for this reason, perhaps, many people do not make a point of sitting while drinking, such as at parties and other functions.
In any event, since the Arizal reportedly ensured to sit before drinking the Kiddush wine, it is certainly proper to sit after reciting Kiddush and then drink the wine.
Summary: When one recites Kiddush on Friday, he should recite "Sabri Maranan" before the Beracha of "Boreh Peri Ha’gefen," even if he recites Kiddush alone. One should stand during the recitation of Kiddush, and then sit so that he drinks the wine in a seated position.
