Sure, here are some useful tips for your visit to Brisbane, Gold Coast, Sunshine Coast and Toowoomba:

Best Time to Visit:
The best time to visit these places in Australia is between May and October when the weather is perfect for outdoor activities and beaches.

Route and Accessibility:
Flights are available from most major cities to Brisbane. From there you can rent a car or catch a train to Gold Coast, Sunshine Coast, and Toowoomba.

Altitude and Acclimatization:
These areas are not situated in high altitudes so acclimatization should not be a problem.

Accommodation and Booking:
All these places have multiple accommodation options ranging from luxury resorts to budget hotels. It's recommended to book in advance especially if you're traveling during the peak tourist season.

Clothing and Essentials:
Pack light and breathable clothing suitable for warm weather but also remember a light jacket or sweater as it can get a bit cooler in the evenings. Don't forget your swimwear, beach towel, sun hat, sunglasses, and high SPF sunscreen.

Health and Safety:
Australia has high healthcare standards. Drinking water is safe, and restaurants maintain good hygiene. Always swim between the flags at the beach as the currents can be strong. It's recommended to have travel insurance.

Local Etiquette and Respect:
Australians are generally friendly and informal. There are no specific cultural etiquette to be aware of in these areas. However, maintain the common practices of politeness and respect.

And given Australia's reputation for animal biodiversity, it's important to give respect to the wildlife, particularly when visiting national parks or the beach. Do not feed or disturb animals. Following the recommended safety guidelines to keep both humans and wildlife safe.

Remember, every one of the areas you are visiting offers something unique. Enjoy your travels!