When you arrive at home from shul, be quick to say Kiddush so you can sanctify the day all the earlier. If you are not yet hungry, you may postpone Kiddush until you are hungry – the meal will be a better mitzva with a hearty appetite. Nevertheless, it is more important to be considerate to your wife, servants, and guests who want to eat already. (ShA1-MB1)
If you have a doubt whether you said Krias Shema too early in shul or not, repeat it before Kiddush. (MB 2)
Kiddush Friday night is a mitzva d’oraisa. Technically, you can fulfill this by daavening Maariv, but people don’t have the intention to be yotzay with Maariv. People know that they will be saying Kiddush at home, and they will have a cup of wine and a meal to fulfill Kiddush the way Chazal instituted it. Therefore you will be fulfilling your mitzva d’oraisa at home over a cup of wine. (MB2)
A child is only obligated in Kiddush mid’rabbonon because of chinuch and cannot be motzi someone who is obligated d’oraisa. (MB2)
A woman is obligated mid’oraisa in Kiddush and can be motzi a man. However it is considered disgraceful if the men are not from her family. (ShA2-MB4)
Kiddush on Yom Tov is d’rabbonon, however it shares all of the laws of Friday night Kiddush. (MB2)
A boy of 13 should not be motzi people that are obligated mid’oraisa. We are concerned, for mitzvos d’oraisa, that he might not have two pubic hairs. If he has a lot of facial hair there is no more concern. (MB 3)
When you are motzi someone, announce first “Have in mind that I am having you in mind”. (MB5)
If two men are being motzi their families, they should not recite the Kiddush at the same time because the listeners cannot hear two voices at once. (MB3)
A boy of 13 is obligated in mitzvos, whereas a girl is already obligated at age 12. (MB6)
Honoring the day meal takes priority over honoring the Friday night meal. However if you only have one cup of wine, use it for Friday night Kiddush since that Kiddush is d’oraisa. (ShA 3)
One way to make sure that the daytime meal has more honor is by eating fish only at that meal and not on Friday night. All of the delicacies of Friday night will not compare to the importance that fish gives to the meal. (ShaT *)
If you do not have wine for Shabbos day, you will have oneg without Kiddush. (MB 8)
Whenever Shabbos begins (or you accept it early), the obligation of Kiddush starts upon you. Do not eat or drink even water before you make Kiddush. (ShA 4-MB 11)
You are allowed to rinse your mouth with water before Kiddush. (MB 13)
If you forget to say Kiddush before the beracha Hamotzi and you have not yet tasted the bread, say the Kiddush before tasting the bread (omit Vychoolu) — but not on wine — the Kiddush will be over bread and will not be considered a hefsek. If you remember only after tasting the bread, say the regular Kiddush over wine. You do not say another Hamotzi. (Rama 5-MB 23, 24, 25)
If you forgot to say Havdalla before the beracha Hamotzi, eat some bread so the beracha won't be l’vattalla, then stop eating and say Havdalla. You can’t say Havdalla over bread. Some poskim hold that you may first finish your meal, then say Havdalla. (Rama 5 – MB 26)
In case you never bentched for bread that you ate on erev Shabbos until it became dark, do not say R’tzay in bentching. If you ate a little after dark as well, include R’tzay. (Rama 6 – MB 30)
If you forgot to say Kiddush before the Friday night meal, say it afterwards. Do not wait until morning. (ShA7 – MB 37)
If you are only saying Kiddush for the first time in the morning, say the Friday night nussach bimkom se’uda. Omit Vychoolu. (ShA 8 – MB 38)
Have a tablecloth spread under the bread and another cloth on top of the bread. According to the Pri Megadim you can uncover the bread after Kiddush, and according to the Chayay Odom it is better to keep it covered until after Hamotzi. (ShA9-MB 41)
The cup of Kiddush has all of the dinim of kos shel beracha already brought above in Siman 183. (ShA 10 – MB 42)
You are allowed to recite Kiddush over a r’viis of wine even if it doesn’t fill the cup. (MB 42)
The Midrash says to recite Vychoolu 3 times. Once during Shemoneh Esray, again after tefilla, and a third time over a cup of wine. (MB 45)
Vychoolu over wine should be recited standing to be motzi your household in the testimony. Others have a minhag to sit down after the first four words that hint to Hashem’s Name. (ShA 10 – Rama)
The best conduct is for all to be seated for Kiddush – it’s easier to be motzi them that way. Even those who’s minhag is to stand, the listeners should at least stand still together to be yotzay. (Rama 10 – MB 46)
Look at the nairos when you begin Kiddush – it's good for your eyesight. Then look at the kos so you won’t become distracted from what you are saying. (Rama 10 – MB 48, 49)
If you have wine only enough for one kos, save it for Havdalla and make Kiddush on bread. If you have more wine, use it for Friday night Kiddush rather than the day Kiddush. (ShA 11)
If you have beer, save the wine for both Kiddushs and make Havdalla on beer. (MB 56)
The minhag of the Rama is to wash netillas yodayim before Kiddush (even when you aren’t saying Kiddush on bread) except on Pesach night. However, many achronim hold to say Kiddush over wine before washing and that is our minhag. (ShA 12 – MB 62, 78)
You need to drink a m’lo lugmuv (cheek-full) of the wine in order to be yotzay Kiddush. This amount fluctuates according to the person drinking. You are allowed one short pause in the middle of drinking the wine. (ShA 13 – MB 68)
It is best for the m’kadaysh to drink the m’lo lugmuv and to give all of the listeners a little wine to taste. If the m’kadaysh didn’t drink at all, you are yotzay as long as one of the listeners drank a m’lo lugmuv. Bedieved, if a m’lo lugmuv was consumed among all of them, they are yotzay as long as they all drank within the time of k’day achillas p’ras. (ShA 14 – MB 71, 73)
The geonim hold that there’s a special din by Kiddush that does not apply to any other kos shel beracha — the m’kadaysh must taste some wine. You should be careful for this, l’chatchila. (ShA 14 – MB 73)
If the m’kadaysh talked (about something unrelated to the Kiddush) before tasting the wine, the Kiddush is still valid — just say another Hagoffen and drink. If the Kiddush cup spilled out, leaving less than a m’lo lugmuv, pour another cup and drink. If you were planning to have more wine anyway, do not repeat the beracha Hagoffen. (ShA 15 – MB 75, 77)
In a case that the listeners have their own cup of wine in front of them (e.g. Pesach night) they may drink even before the m’kadaysh. (ShA 16)
The listeners do not need some wine of the m’kadaysh to be poured into their cups (unless their cups are pagoom. See above Siman 182). (ShA 17)
When all are tasting directly from the kos shel beracha of the m’kadaysh, they are considered like the m’kadaysh himself and the kos is not considered pagoom. (ShaH 89)