Concerning my own practice, it's something that's evolved over time. I do some chants as part of my daily Zazen (which among other things gives it more structure than simply plopping myself down on the zafu
), others are done at various times of the day as an intermittent reminder of my commitment to practice. Currently, the chants/verses surrounding my daily Zazen are: the Verse of Atonement (
sange mon), the Three Refuges (
sankie mon), before putting on my Rakusu, the Robe Verse (
takkesa ge) and just before Zazen, the Four Vows (
shigu sei gan mon). Aside from that and at various times of the day, I recite the (prescribed Treeleaf) Metta and meal chant (
gokan no ge), as well as the Heart Sutra.