It is good to learn a little Torah before the seuda. (MB 5)
The table should be set, furniture in order and cloth should be spread under the challahos and on top of them — just like at the seuda on the night before. (ShA 1 – MB 1)
For Kiddush, some customs begin with V’Shomru or “Z’chor es yom haShabbos…”. It is incorrect to begin with “… al kayn bayrach…” since it is only part of a possuk. If Moshe Rabaynu didn’t split the possuk we aren’t allowed to either. (MB 2)
After Kiddusha Rabba, wash netillas yodayim, have lechem mishna, and eat the meal. After you have eaten your fill, sing zemiros. (ShA 1 – MB 5)
Once you are obligated in Kiddush, you aren’t allowed even to drink water. When are you obligated in Kiddush? When you can have a seuda, so it depends upon the laws of Tefillah (Siman 89) : Normally you aren’t allowed to have a seuda before Shacharis – so you aren’t obligated in Kiddush before Tefilla. However a person who needs to have a seuda early before Shacharis because of medical reasons, must say Kiddush before his meal. (ShA 1 – MB 7 – BeH “chovas”)
Wine is the mitzva min hamuvchar. If you enjoy whiskey it is also l’chatchila. Otherwise if you don’t have those, make Kiddush on chammar medina (but not water) . (ShA 2 – MB 8)
If you have no mashke for Kiddush, eat without it. If someone brings you mashke in the middle of the meal, say Kiddush on it right there and then. (ShA 2 – BeH “oichel”)
If you don’t have mashke for Kiddush, do not eat anything before you have bread for your seuda. (It doesn’t have to be a whole loaf.) If you don’t even have bread, eat for oneg Shabbos without it. (MB 10)