8 Shavuos Customs of Maran Rav Chaim zt”l

Rav Chaim zt”l did not put grasses, trees, or plants in his home nor in the Lederman shul on Shavuos. This was in accordance with the view of the Vilna Gaon (see Mishna Brurah 494:10).
Rav Chaim zt”l avoided getting a haircut on Erev Shavuos itself, because of the danger involved in letting blood that day. He was concerned
Rav Chaim zt”l stayed up all night on Shavuos and studied. (See MB 494:1)
After Chatzos, Rav Chaim zt”l would recite the tikkun leil shavuos.
After also hashachar, and before shacharis Rav Chaim would immerse in the Mikvah. When the infirmities of age made this too difficult, he stopped.
He would have the Megillah of Rus read from a klaf and with a bracha.
He would consume milchigs in the morning seudah on Shavuos – without having meat in the same meal.
When he was able to do so, he would stand during the recitation of akdamus.