Um... he kinds uses the walls completely wrong. Those are roof tiles. Please don't take his as good mapping. >.<;
His sizes might be down but yeah, wrong tile usage and all. What I suggest is to make your maps a bit more compact. They aren't bad, really, just very big. Cut the rooms in half but keep the same amount of stuff (if not more) in them. That should help a lot. Keep in mind that the player only needs one tile 'roads' to get through. 2-3 can be okay in rooms that are supposed to be larger, but sometimes smaller is better.