There are two ways in which to make the full Spiritual Exercises of St. Ignatius.
You can go off for thirty days, usually to a retreat house, usually with a group of people doing the same thing, and spend your time in silence, meeting with a retreat director every day to discuss your prayer life as you make your way through the pattern of prayer "exercises" suggested by Ignatius and deeper into relationship with God. The advantage? Thirty days of concentrated time with God. The disadvantages? Time, money, those sorts of things . . .
Or you can do what's often referred to as a "retreat in daily life" or a "19th Annotation retreat" (so named for one of Ignatius' annotations in the book used by spiritual directors to companion others through the Exercises) ~ stretch the 30 days to 30 weeks (or more), spend an hour or so a day in prayer, rather than several hours, and meet with a director each week rather than each day. (This is how I did it.) The advantage: Daily life experiences becoming a part of an intense prayer life. The disadvantage: Daily life experiences getting in the way.
Some folks make 19th annotation retreats in concert with others; many retreat houses offer them during the academic year, with varying degrees of contact among group members. The advantages: Structure, expense, perhaps community. The disadvantage? The loss of the individuality of timing and often, therefore, of the journey itself.
I'm accompanying someone through the 19th Annotation these days. We've been at it for about four months now, and I am remembering something my own 19th Annotation director often says: When you see someone's entire life becoming wound up in the prayer, you know the retreat is starting to take hold.
It's really and incredibly wonderful, to listen in as someone makes connections between the stories of the gospel and the events and challenges of his or her own daily life. and begins to find in every ongoing thing ~ family life, work plans, relationships, memories, celebrations, crises ~ threads of God's love and activity previously unnoticed.
This is the best thing I get to do.