Brian McLaren wrote the intro: Finding Our Way Again. He has some annoying bees in his bonnet. Careful analysis is not his strong suit, and phrases like “the Abrahamic faiths” do not inspire confidence in his powers of observation. Nevertheless this is the best written of the set, and has some worthwhile material: such as the breakdown of the purposes of disciplines into katharsis/via purgative (purification from evil), fotosis/via illuminativa (receiving God’s truth and light), and theosis/via unitiva (unification with God). The three themes sometimes go together, but often one prepares the way for others.
Scott McKnight wrote Fasting, in which he says “Fasting is the natural, inevitable response of a person to a grievous sacred moment in life.” He’s not so keen on instrumental fasting, except when he is. It turns out that instrumental fasting (to seek more intense prayer, discipline the body, etc) has long roots in tradition. Chapters are “Fasting as” “Body Talk”, “Body Turning”, “Body Grief”, etc; but these metaphors didn’t seem all that useful. He distinguishes between fasting (food/water) and abstinence (everything else). Important point: don’t be an idiot about fasting.
Dan B Allender wrote Sabbath. Feast day, day of delight, but not a day of amusement. This is an impressionist-style book, and I think he was paid by the word.
Joan Chittister wrote The Liturgical Year. Short version: it’s a good thing, and the calendar isn’t about us but about worship and growing in worship. (Another paid by the word.)
Robert Benson wrote In Constant Prayer. Short version: Praying the Office is good prayer in itself, good for corporate worship, and also good training in prayer. My late brother-in-law recommended that decades ago; I’ve been kind of spotty in practicing it. Making sure there’s time is the hard part of any discipline.
Nora Gallagher wrote The Sacred Meal. I randomly opened to a page where she equated the Eucharist and feeding the homeless. I checked another and she was approvingly citing Bishop Spong. I didn’t think I’d learn much about orthodox tradition from Spong, and set the book aside.
I should see if the book about pilgrimage is handy somewhere--that's one discipline I haven't learned much about.