Here's an ideal itinerary for 5 days in Tulum:

Day 1: Arrival and Beach Time

• Arrive in Tulum and check into your hotel or Airbnb
• Spend the day relaxing on the beach and soaking up the sun
• Head to one of the many beach clubs for drinks and dinner, such as Papaya Playa Project or La Zebra

Day 2: Cenotes and Ruins

• Start the day early with a visit to the Tulum Ruins, which are located right on the beach
• After exploring the ruins, head to Gran Cenote or Dos Ojos Cenote for a refreshing swim in the crystal-clear waters
• In the evening, enjoy dinner at Hartwood, a popular restaurant known for its farm-to-table cuisine

Day 3: Sian Ka'an Biosphere Reserve

• Take a guided tour of the Sian Ka'an Biosphere Reserve, a UNESCO World Heritage Site that is home to a diverse range of wildlife and ecosystems
• Stop at the Muyil Ruins, which are located within the reserve and offer stunning views of the surrounding jungle and lagoons
• End the day with a sunset boat ride through the mangroves

Day 4: Yoga and Shopping

• Start the day with a yoga class at one of Tulum's many yoga studios, such as Yoga Shala or Sanara
• Afterward, explore the town's boutiques and shops, which offer everything from handmade jewelry to locally made textiles
• In the evening, head to Gitano for cocktails and live music under the stars

Day 5: Beach Day and Farewell Dinner

• Spend your last day in Tulum relaxing on the beach and enjoying the warm Caribbean waters
• In the evening, have a farewell dinner at Arca, a trendy restaurant that serves modern Mexican cuisine with a focus on local ingredients

Of course, this itinerary is just a suggestion - feel free to mix and match activities based on your interests and preferences. Enjoy your trip to Tulum!