Tours can use a combination of public transport systems such as taxi BTS skytrain and ferry boat.
Where possible I love to add in an iconic tuk-tuk ride too.
The best combination of transport is determined by where your hotel is located and what you want to experience. I try to use the most scenic and expedient means possible.
This can be a fun option during the cooler months, but I highly recommend sticking with our chauffer driven vans during the hot and rainy months as the heat can be debilitating and public transport has little air-conditioning.