After such an elevated Yom Tov Pesach and after the much work and money that went into preparing for Pesach, we need to make sure that we keep the light burning.
Chasidus has many teachings as to how to keep the Ohr of Yom Tov within us. In Belz the Rebbes repeated the Ramban in Sefer Emunah Ubitachon that one needs to create a “Kli” to keep the Ohr. The Kli can be many things; here are two examples. 1) A person can undertake on Yom Tov an improvement in their day to day life that they can uphold, thus continuing the inspiration of Yom Tov. 2) Performing a Mitzva right after Yom Tov that involves action brings out the inspiration of the heart to action.
The Shabbos after Pesach, Shavuos, and Succos are special by Chasidim. The first Shabbos after Succos is called Shaboos Bereishis. The name is for the Parshah and the beginning of reading the Torah anew, but the Avoda of Shabbos is also to continue the Ohr of the Yomim Noraim. The Shabbos after Shavuos is called in Yiddish “Shabbos Nuch Shavuos”. Simply it means Shabbos after Shavuos, but Chasidim translate it as Shabbos ‘more’ Shavuos.
The Shabbos after Pesach is called differently in the different streams of Chasidim. In Belz it is called, “Shabbos Gelle Matzos”. Literally it means, Shabbos Yellow Matzos. See below on the meaning of this name.
All these three Shabbosim continue the Ohr of the previous Yom Tov to the whole year.
There was an opinion that singing the tune of the Tefillos of Yomim Noraim is not good since it invokes Dinim. The Imrei Chaim of Viznitz strongly opposed this idea. “When a Yid wants a Hisoreros in the middle of the year and sings the Nusach of Yomim Noraim, it invokes great Rachamim, not Dinim”.
The Divrei Torah, the Nusach, the Niggunim, and even remembering the smell of the Maror and Charoses can all be used to reawaken the impression and Hisoreros we had on past Yomim Tovim and times of elevation.