Sure, traveling to these beautiful Spanish cities is going to be a wonderful journey. Here are few travel tips:

Best Time to Visit:
The best period to visit these cities in Spain would be Spring (March to May), and Autumn (September to November); the temperatures are mild and the tourist crowds are smaller. Remember, the summers can be extremely hot and winters can be completely opposite.

Route and Accessibility:
All these cities are well-connected by high-speed trains (AVE trains) and buses. You can also consider taking domestic flights. Car rentals are also an option if you're comfortable driving.

Altitude and Acclimatization:
These cities are not situated at high altitudes so there's no need to worry about acclimatization. You can simply enjoy your time exploring these cities.

Accommodation and Booking:
From luxury hotels to budget hostels, these cities provide a wide range of accommodations. It's recommended to book in advance, especially during peak tourist seasons. Airbnb is also a popular choice amongst travelers.

Clothing and Essentials:
Pack according to the season of your visit. Summers require cool, breathable clothing; while winter requires warm clothes. Always carry a comfortable pair of shoes as there is plenty to explore on foot.

Health and Safety:
Spain is generally a safe country, however, pick-pocketing can be frequent especially in tourist crowded areas. It’s advisable to keep your documents, money, and other valuables secure and to carry a copy of passport with you.

Local Etiquette and Respect:
Spanish people are very warm and friendly. They appreciate greetings, so a simple 'Hola' (hello) or 'Gracias' (thank you) goes a long way. Also, respect the local customs, for instance, avoid loud talking in public places. Don't forget to enjoy the local cuisine, Tapas and Paella are a must try!