I took the free tuk-tuk ride to Krung Thon Buri station to take a BTS to Saphan Taksin station. From there, there was signs and a walkway to Sathorn pier. I had planned to go to Wat Arun, so my next pier stop was Tha Tien.
To reach Tha Tien pier, you need to take the orange-flag boat. It’s not necessary to buy a ticket. You can pay on board. It’d be better to prepare the money beforehand. It costs about 14 Baht per trip. During peak hours, the boats are usually full. Beware of pickpockets.
You can also buy Chao Phraya Tourist Boat ticket at the locket at Sathorn pier. It costs 150 Baht. The ticket can be used for a whole day (on the stamped date) and you can get on or off wherever you want. The tourist boats have blue flag. I recommend you get this ticket if you are pressed for time and would like to go to a lot of places along the river in a day. However, if you are like me, who want to explore every site you go to, then this ticket is a waste of money, considering it only costs 15-20 Baht per trip by taking an orange or yellow-flag boat.
For more info on boat services and fares, go to http://www.chaophrayaexpressboat.com/en/services/index.aspx
Here’s some pictures I took on my way along the Chao Phraya river.