Josh:

A couple of thoughts—

—when a project involves reading lengthy works, I make a set page count per day the Next Action (eg. read pages 1-100, read pages 101-200, etc.) Whatever daily page amount works for you and your schedule.

—on writing longer projects, I either (depending on the kind of writing project):

break the project down into discrete Next Actions such as Complete research reading or Outline first draft or Brainstorm topics onto note cards, etc. or give myself a daily quota (write five pages of the first draft or rewrite pages 1-20—you get the idea)

The challenge is simply to break the big stuff down into a series of Next Actions. Doing this lets you spread the work out over how every many days you need to given your schedules.