EREV TAVSHILIN: WHY AND HOW
THE BASIC REQUIREMENT
Ideally two types of food, one cooked and one baked, are set aside (they can be placed in a fridge with other food as long as they are placed apart and not eaten until Shabbat). A blessing is recited (this can be found in a Machzor or in the Artscroll Siddur on p. 654/655). The blessing is followed by the recital of a short paragraph. Since the meaning of the text must be understood in order for the eruv to be valid, the text should be recited in a language that one understands.
The cooked food should be the type of food which is served as a main dish, e.g., meat, fish or eggs.
Only one eruv tavshilin per household is required. It includes all of the people who reside in the house, including married children and guests who are spending the Yom Tov as part of that household.
One who forgot to prepare an eiruv tavshilin on erev Yom Tov before sunset may not cook on Friday for Shabbat. There are several strategies that can rectify this oversight, but they are too complex to describe here and should only be implemented with rabbinic guidance.
The Eruv Tavshilin has no connection with the laws of Eruv made to allow carrying in a city on Shabbat.