You bet! If you want total control of your trip itinerary from start to finish, select "I want to plan it myself" or toggle Autopilot OFF when you're starting a new trip and you can manually create your trip as usual.
If you do create your trip manually and you're a Premium member, you can still leverage Autopilot to add waypoints to that trip if you need a recommendation. You can learn more about that here: Using Autopilot to Enhance a Trip