Some things you work on in almost every session - clearing your inbox, writing for twenty minutes, reviewing the day. Put those on the Recurring tab of the Tasks page. Recurring tasks have no checkbox there: you add, edit, reorder and remove them only on that tab.
In any lobby or room, open Add from My tasks and you will see them under "Recurring". Adding one makes a copy for that session (marked with a small ↻), which you tick off during the hour. The recurring entry itself never changes and is offered again next time.