Certainly, visiting the coastal cities of Cairns, Townsville, Mackay, and Rockhampton will be a delightful experience. Here are some travel tips for your journey:

Best Time to Visit:
Ideally, the best time to visit these coastal Australian cities is during the winter season from June to August when the weather is cooler and comfortable for outdoor exploration.

Route and Accessibility:
These cities are well-connected by road and have airports with regular flights to major Australian cities. Consider renting a car if you plan on road-tripping through these cities.

Altitude and Acclimatization:
These cities are located at sea level, so there should be no concerns about altitude sickness. Do remember to stay hydrated, especially during the hot summer months.

Accommodation and Booking:
There's a wide range of accommodations available in these cities, from budget hostels to luxury resorts. It is recommended to book your accommodations in advance, especially during peak tourist seasons.

Clothing and Essentials:
Comfortable clothing and footwear are recommended as you might be spending lots of time exploring outdoors. Don't forget a swimsuit for beach visits and a good sunscreen to protect from the Australian sun. A hat and sunglasses would also come in handy.

Health and Safety:
Ensure to follow the safety signs and instructions at the beaches as Australian coastal currents can be strong. If hiking in parks or nature reserves, keep an eye out for potential wildlife.

Local Etiquette and Respect:
Australians are known for their friendliness and relaxed demeanor. Be respectful of the local environment, especially the Great Barrier Reef and its surrounding ecosystems if you plan on visiting. Don't forget, in Australia, tipping is appreciated but not mandatory.