How is it done?

The foods:[1] The owner of the house takes a [whole[2]] loaf/role of bread/Matzah the size of a Kibeiytza[3] [which is to later be used on Shabbos[4] for the meal[5]] and a Kezayis[6] of a cooked[7] piece of meat or other food[8] which one eats together with bread.[9] Nevertheless initially it is best to use an honorable food, such as meat or fish.[10]

Being Mizakeh on behalf of others:[11]  The custom is to acquire the food to all the other members of the city in order to merit them with the Mitzvah in case someone forgot to do so.[12] This is done through placing the food into the hands of a non-family member[13] or one’s married son[14], or any child above Bar/Bas Mitzvah which supports himself/herself. After the food is placed in their hands the owner of the house says “I hereby acquire [this food] to all those that want to acquire and rely on this Eruv”.[15] The person then lifts up the food one Tefach from its current area, hence acquiring it for the townspeople.[16] The owner then takes back the food and recites the blessing of “Al Mitzvas Eruv” as explained next. If there is no non-family member or married son available then one may give it to one’s wife, or one’s child who is over Bar Mitzvah, to lift up one Tefach and acquire the Eruv to the city members.[17] However children under the age of Bar Mitzvah which are supported by the household may not be used for this acquisition.

The blessing: One says the following blessing upon making the Eruv Tavshilin: “…Asher Kidishanu Bemitzvosav Vetzivanu Al Mitzvas Eruv”. After the blessing one says in a language that he understands “With this Eruv it will be permitted for us to bake and cook and insulate foods, and light candles and do all our needs for Yom Tov to Shabbos”.

Reminding the public:[18] In those years that Eruv Tavshilin must be performed it is proper to place signs by the public areas [i.e. Shul; Mikveh; Website] in order to remind the public of this matter. [It is suggested to also announce this in Shul at the conclusion of Shacharis and prior to Mincha.[19]]

Summary: Whenever Yom Tov falls on Erev Shabbos one performs an Eruv Tavshilin on Erev Yom Tov. The owner of the house takes a whole loaf/role of bread/Matzah the size of a Kibeiytza [which is to later be used on Shabbos] and a Kezayis of a cooked piece of meat or other food which one eats together with bread. If one has another person to use to acquire the food to him on behalf of the city then the owner is to say: “אני מזכה לכל־מי שרוצה לזכות ולסמוך על ערוב זה”   The person who is acquiring the food for the townspeople then lifts the food up one Tefach. The owner then takes back the food and recites the following blessing: [If one does not have another person to use to acquire the food to the townspeople then he is to simply hold the food and begin from here with the following blessing:]   ברוך אתה ה’ אלוקינו מלך העולם אשר קדשנו במצותיו וצונו על מצות עירוב.   After the blessing one says in a language that he understands “With this Eruv it will be permitted for us to bake and cook and insulate foods, and light candles and to do all our needs on Yom Tov for Shabbos”.   בדין יהא שרא לנא לאפויי ולבשולי ולאטמוני ולאדלוקי שרגא ולתקנא ולמעבד כל צרכנא מיומא טבא לשבתא לנא ולכל ישראל הדרים בעיר הזאת

Q&A May one use bread and cooked meat that is frozen for the Eruv Tavshilin?[20] Yes.