I think we have to stay in at least one motel type place. They are pretty iconic and I doubt we'll ever get back to that side of the states so I reckon that's a must do
We drove route 1 and planned to do it all in motel type places, but tbh some of them looked pretty shady, like the type of place you'd definitely get murdered (we watch too much TV!) so we mostly ended up in Homewood suites type hotels.
We stayed in a motel in Cambria for just one night, there were rows and rows of motel type places, but really nice ones, overlooking the ocean. Loved it!
Stopped for coffee and cake at the Madonna Inn and that was enough 
Handy hint if you like tea and coffee, take/buy a kettle. All the hotels we stayed in had a coffee pod machine, but the pods provided made vile coffee, so we bought our own Starbucks pods at the local supermarket and also lugged a kettle around with us that we picked up in Walmart for making tea #britsontour 
I'd recommend longer than a night in San Diego, its lovely but we rushed on so feel we could happily have stayed longer. San Fran was interesting but wouldn't go back, having done Alcatraz (we watched the movie the night before we went, which made it all the more interesting so we knew the story about the escape)
Laguna Beach was lovely, loads of boutiquey shops and galleries - I ran along the beach keeping up with a sealion who was playing in the sea!
Monterey was pretty and the aquarium was nice enough, but not the best I've ever been to. Whale watching boat trip was wonderful.
Photo is from our motel room in Cambria. One of our favourite holidays for sure. Have an amazing time.