Jose Rafael Maldonado, Miguel Andrango's son-in-law, now runs the day-to-day operations of this internationally famous weaving family business, in its fourth generation of creating fabrics entirely by hand (except for that one spindle made of old bicycle parts). You can see the entire workshop for the cost of a donation, but you may also stick around and learn the process for $25 per day. Here in Agato, it's old-school all the way. It's best to call in advance before visiting.
You can walk uphill 2km from the Peguche waterfall; just follow the cobblestone road. At the top of the hill, where the main road comes through, turn left and look for the workshop sign. Cooperativa Imbaburapac buses (red and blue in color) go through Peguche en route to Agato from Otavalo. You can sit it for longer multiday workshops if it suits your fancy. The Andrango family also sells their product at the Hacienda Cusín.