This is what our itinerary looked like:
Day 1: Stay overnight at the Stansted Airport in London for our flight that leaves early morning the next day. It was pretty bad. There were hardly benches, and it was freezing cold in there.
Day 2: Take an early flight out to Barcelona with Ryanair. But Ryanair only flies to Girona, so we had to take a Ryanair coach from Girona to Barcelona (which took about 1 hour). We arrived in Barcelona around noon, took the metro to Jaume I, and had to find our apartment (right behind the Town Hall in Barri Gotic), whcich was in a very central location. Then we went around Barri Gotic and La Rambla. We got some Catalun pizza in a restaurant in La Rambla. It had a superb taste, but we had no idea how much that cost till we had to pay for it (about 8 euros). Then walked around La Rambla to the cool market and some touristy shops nearby. We went to the Picasso museum in the late afternoon. It was really quite scary walking the narrow streets of Barri Gotic. Even though it was very well-lit, a lot of times you felt you were the only one walking on the street. It was a bit claustrophobic, too. We went back to our apartment and COOKED our own dinner!
Day 2: Parc de Joan Miro -> Pablo Espanya -> Casa Batllo, Casa Amatller, Casa Mila (didn't go in)-> Sagrada Familia (didn't go in) -> Parc Guell -> shopping for souvenirs -> Placa Catalunya & La Rambla -> back to apartment -> Port Vell (seafront, where the statue of "Face of Barcelona" is), where we found an okay restaurant and got a decent meal for 15 euros
Day 3: I just can't imagine coming to Barcelona without going into Casa Mila. I felt I would deeply regret that so I went to Casa Mila by myself. and I was right! If I have not gone there, the thought of "could have been there" would really torture me. I totally loved the house, but it's too bad I didn't have a lot of time to look around. I had to get back to our apartment to check out within 50 minutes, so I basically flew back and got there right on time. (You can't believe how far one has to walk to transfer from the different metro lines!) and went to the Girona airport to take a bus to Girona. We spend an afternoon in Girona, which was enough. and there were lockers (left luggage) in the train station (right beside the coach station), so it was very convenient (there were none in the airport). We got back to London Stansted around 12am and had to sleep in the airport again because there weren't trains going back to East Sussex at that hour.
Day 4 - We caught the earliest train back to East Sussex and really FAUGHT for it. We ran as fast as we could to our connection from Victoria Station. It was pretty intense!