Any recommendations for a guided day trip to Sintra from Lisbon?
https://www.portugaljourneyswithpeppe.com/
Used Peppe last month and he was excellent!
I would highly recommend Jose from Lisbon On Wheels. We booked a private tour with him and he allowed me to customize it. He picked us up at our hotel at 9 am and brought us back after 7. I can't praise him enough and neither can fellow travelers. He has excellent reviews on Trip Advisor.
This is easy DIY using Bolt/Uber directly from your hotel.