To get there from Bangkok, you need to go to the Southern (Sai Tai Mai) bus terminal. We took a shuttle bus from Don Mueang Airport to the bus terminal. When you get there, you'll notice that there are two terminals on either side of the road. each with buses going the opposite way. Just ask someone where to buy the ticket to Maeklong and they will point you to the correct one.
Our flight landed in Bangkok at around noon. By the time we got past immigration and customs and waited for the shuttle bus, it was close to 2 pm. Then there was the ride to the bus terminal, plus the wait for the next minibus to Samut Songkhram. I was really hoping we could see the 3:30 pm train going through the market. That way, we could make our way back to Bangkok before it got dark. However, at 3:40, we were still stuck in traffic. Our only hope was for the train to be delayed, as trains in some Asian countries are notorious to be. Unfortunately, the train was on time. Here's the latest schedule for your reference.
The next (and last) train of the day was in another 2 hours, so we spent our time exploring the area while having the indisputably best iced tea in the world: the Thai iced tea.
Several street snacks later, we walked back to the railway track and waited. Some other tourists were also waiting restlessly with their cameras poised and ready. Finally, we heard the horn coming from the distance. It still took a long time for the train to come into view after the first sound of the horn. So if you hear the sound and you're still struggling to get your camera out of your backpack, don't worry. The train moves very slowly so that people have enough time to clear the track.
At 5.30 in the evening, most of the market vendors had already gone home. There were only a few left at the stretch we were at. I wondered if they stayed behind simply to give us latecomers a photo opportunity. Anyhow, the spectacle wasn't as remarkable as the ones you might have seen in videos where the market is in full swing and you get to see how the vendors calmly retract their umbrellas just a few seconds before the train passes by and then put them back up right after.
The only good thing about arriving late was that there was not much crowd left, so we didn't have to fight for a good spot to take pictures. As the sun was setting, my partner captured this beautiful shot against the sunset:
Also, we got to take a picture with the train as it stopped at its last station for the day:
