The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) writes (listen to audio recording for precise citation) that one should recite the Berachot over the Lulab and Etrog before taking hold of the Etrog. (On the first day of Sukkot, one recites two Berachot – “Al Netilat Lulab” and “Shehehiyanu” – whereas during the rest of Sukkot, we recite only “Al Netilat Lulab.”) However, one should ensure to take hold of the Lulab before reciting the Berachot.
If a person has a bandage or gauze over a wound on his hand, he must remove it before taking the Lulab and Etrog, so that there is no Hasisa (interruption) between his hand and the Lulab or Etrog. The Ben Ish Hai cites an opinion requiring one to remove any rings from his fingers, as well. He rules that if a person took the Lulab and Etrog with a Hasisa on his hand, he should take the Lulab and Etrog again, though without a Beracha.
One must ensure that the Shidra (“spine”) of the Lulab is facing him when he takes the Lulab and during the Na’anu’im (waving of the Lulab).
It is forbidden to eat before performing the Misva of Lulav and Etrog. One may, however, drink coffee before performing the Misva, just as one may drink coffee before praying in the morning.
One must stand when taking the Lulab and Etrog. The Ben Ish Hai emphasizes that even an ill patient should remain standing while performing this Misva.
One must hold the Lulab in his right hand and the Etrog in his left hand, both when performing the Misva of taking the Arba Minim and during the Hakafot around the Teba. The Ben Ish Hai laments the fact that many people hold the Lulab and Etrog together in the same hand during the Hakafot, and use their other hand to hold the Siddur. This is incorrect; even during the Hakafot, the Lulab and the Etrog should be held in different hands. However, the Ben Ish Hai adds, the Lulab and Etrog should be held closely together, such that they touch one another. He cites from the Sha’ar Ha’kavanot that specifically the bottom of the Etrog should touch the Lulab. One should therefore tilt the Etrog slightly so that the bottom touches the Lulab, rather than holding them parallel, in which case only the middle section of the Etrog touches the Lulab.
During the Hakafot on Sukkot, we encircle the Teba while holding the Arba Minim. The Ben Ish Hai rules that even if a synagogue does not have a Torah scroll, the congregation nevertheless performs Hakafot and encircles the Teba, since the Hakafot depend upon a Teba, not a Sefer Torah. He writes that if a person cannot attend the prayer service in the synagogue, due to illness or other extenuating circumstances, there is no value in placing a chair in the middle of the room and walking around it with a Lulab and Etrog. However, he adds, it would be appropriate to place a Tanach on a chair and then walk around the chair so that he does not lose completely the Misva of Hakafot.