Yom TovHalachos of The Ten Days of Repentance

Some are stringent not to eat until one is completely full during these days, even on Rosh Hashanah or Shabbos shuva (except erev Yom Kippur). [1]תקצז,א

One should refrain from eating pas akum during these days [2]תרג,א .

One should examine his actions before one go to sleep at night.

The seven days between Rosh Hashana and Yom Kippur correspond to the days of the week, and on each one, he should do teshuva on any sin he did on that day over the past year.