Absolutely, Spain's coastline towns of Alicante, Denia, and Torrevieja are a treat to visit. Here are some key tips you might find helpful for your journey:

Best Time to Visit:
Consider planning your visit between May and October when the weather is warm and sunny. The sea temperature during these months is perfect for swimming.

Route and Accessibility:
Alicante is the primary travel hub among these locations. Alicante Airport is well connected with many European cities and is about an hour's drive from Torrevieja and Denia. You can find public transportation options like bus and tram services. Renting a car can also be a suitable option for flexibility.

Altitude and Acclimatization:
These coastal towns are at sea level, so there won't be much altitude adjustment to worry about. Still, you should acclimatize to the Mediterranean heat by staying hydrated and using sun protection.

Accommodation and Booking:
There's a range of accommodations to suit every budget, from luxury hotels to budget-friendly hostels and vacation rentals. It's highly recommended to book in advance, especially if you're traveling during peak season.

Clothing and Essentials:
Pack summer clothing, a swimsuit, beachwear, and a good sunscreen. A hat, sunglasses, and comfortable walking shoes would also be useful. If you're planning to visit some of the stunning local churches, be sure to pack modest clothing.

Health and Safety:
Follow the general safety rules, like not leaving your belongings unattended. Also, stay hydrated and use sunscreen to avoid any heat-related issues.

Local Etiquette and Respect:
Locals in these towns are friendly and welcoming. Do respect their local customs and traditions. Tipping is customary in Spain, traditionally 10% to 15% in restaurants. And as these are coastal towns, be environmentally conscious and do not litter the beach. Enjoy your trip!