I've learnt a bit about photography and my camera since my trip in Europe last year. All the same it took a bit of trial and error to get settings that were going to deliver sharp enough pictures while the train was in motion. My aim was to get the shutter speed to 1/2000 or below. That meant raising the ISO higher than I'd like to, but in the end I think the results are worth it. Unfortunately I has meant that many pictures were taken with a wide aperture with a somewhat narrow depth of field.
I was able to flip between my newly discovered focus modes to try and get the right one with the right metering. Having said all that, the trick was more about framing and focusing the shot and then quickly taking it before a tree, pole, sign, freight train or other obstacle got in the way. Not an easy thing to do. And a large number still had focus problems after all that. So I worked on the principle of taking as many as I could to increase the likelihood of some decent ones and, hopefully, a few really good ones. In the second half of the trip I used the continuous shooting mode which gave me more shots to choose from. Wish I'd thought of that earlier.
For a while I used the 50mm lens I'd bought for Europe. It certainly helped keep the shutter speed low, but I just wasn't getting enough of the scenery in the frame at once, so I reverted to my newer 18-200mm lens for most of the trip. That also allowed me to really zoom in when required.