At this point, you roll it up in bubble wrap (or bamboo).
Here's when I took a diversion. I felted in the dryer. It feels like cheating. Roll it up in the plastic, then roll it up in a towel. Secure it, and pop it in the dryer for ten minute increments. Air dry. No heat. Pull it out and re-roll the bundle after every ten minutes. I did this four times. In the meantime, I layed out another scarf! Trying to make good use of time!
After it appears to have firmly migrated and felted, it needs to be fulled. I like to use a washboard with hot, soapy water. Then I throw it until it looks pebbly and has shrunk.