The question was: Is it advisable to pre-book accommodation, en-route, if so how to go about this in el Camino de Santiago?
Regarding the matter of booking or not booking accommodation in El Camino de Santiago I have firstly to clarify one thing: you have to decide if you want to sleep in the specific hostels for pilgrims (called “albergues” in Spanish) or in normal hostels or hotels.
If you want to sleep in albergues (there are public or private ones) you will never need any kind of booking, simply because they don’t book or reserve places. This is the most common option between pilgrims.
If you need some more privacy or luxury, you can sleep in conventional hostels or hotels, or another popular option in Spain is rural houses (“casa rural”). You can book them, although sometimes is not necessary, especially in low season because you can just arrive and normally they would have room for you. In medium size villages and towns there are several hostels and hotels to choose. If you are walking el Camino de Santiago in summer and want to be completely sure you will have your room, the best thing to do is to buy a Camino de Santiago guide book from our Store, maybe the one by J.Brierley is a good choice. Take the guide with you in El Camino de Santiago and phone the hostels the day before to make a reservation.