Here's an ideal itinerary for 6 days in Perth:

Day 1: Arrival and City Tour

• Arrive in Perth and check into your hotel
• Take a city tour to get your bearings and see some of the top sights, such as Kings Park, Elizabeth Quay, and the Perth Mint
• Enjoy dinner at one of Perth's many excellent restaurants

Day 2: Rottnest Island

• Take a ferry to Rottnest Island, a beautiful island just off the coast of Perth
• Rent a bike and explore the island's stunning beaches and natural beauty
• Meet the friendly quokkas, a unique marsupial found only on Rottnest Island
• Enjoy a seafood lunch at one of the island's restaurants before returning to Perth

Day 3: Swan Valley Wine Tour

• Take a wine tour of the Swan Valley, a picturesque wine region just outside of Perth
• Visit some of the region's top wineries and sample their wines
• Enjoy a gourmet lunch at one of the wineries or at a local restaurant
• Return to Perth in the evening and relax at your hotel

Day 4: Fremantle and Beaches

• Visit Fremantle, a charming port city just south of Perth
• Explore the historic Fremantle Prison and the Fremantle Markets
• Enjoy lunch at one of the city's many cafes or restaurants
• Spend the afternoon at one of Perth's beautiful beaches, such as Cottesloe or Scarborough
• Watch the sunset over the Indian Ocean before returning to Perth

Day 5: Perth Hills and Wildlife

• Visit the Perth Hills, a beautiful region just east of Perth
• Explore the quaint towns of Kalamunda and Mundaring
• Visit the Perth Hills Discovery Centre and learn about the region's flora and fauna
• Meet some of Australia's iconic wildlife at the nearby Caversham Wildlife Park
• Return to Perth in the evening and enjoy dinner at a local restaurant

Day 6: Perth Cultural Experience

• Visit some of Perth's top cultural attractions, such as the Art Gallery of Western Australia, the Western Australian Museum, and the Perth Cultural Centre
• Enjoy lunch at one of the city's many cafes or restaurants
• Spend the afternoon shopping in the trendy neighbourhood of Northbridge
• Return to your hotel and prepare for your departure the next day

I hope this itinerary gives you a good idea of what to do during your 6 days in Perth. Have a great trip!