Awesome work! I always wonder how everyone made the grass using MMP like one near the river...
Mine is quite easy to do. usualy the ground (where the habitations are) is 15m high, and the river banks just as the high of the river, so i can still place trees.
Then after than I just draw the paths using
Chrisadams' paths (the gravel paths does the work perfectly). The grass is a mixture of
Chrisadams' Green Grass and
Girafe's Cattails (the evergreen version).
I usually add some bushes and trees after while.
if you want, and if you find it useful, I can try to make a quick tutorial about that.
I'm inspired to give HSR a try when I view your cities since you make it look so good. BTW, is your Shinkhensen HSR-based or el-rail-based?
HSR is definitely a good addition to try! With the correct mods it gives a good look of a modern high speed rail train. Not too modern though, as I don't like Sci-fi things. (and the basic look of the HSRP is a little too Sci-fi in my opinion.)
The only thing that bugs me is the lack of proper sized HSR stations.
Lets see for reference different High Speed Train around the world. A single TGV ( ten cars and two engines) is 240~ meters long. A double one ( they usually come double) is 480meters long. The Japanese Shinkansen is 400 meters long (Fourteen cars and two engines).
Taking these lengths into account, that makes a stations at least 480m long for the TGV. A SC4 tile is 16*16m (if i remember correctly).. 480/16=30. A normal sized HSR station should be 30
stations tiles in the game. Quite long eh? well definitely better than the tiny 4~10 tiles one. i'm working on Shin-Kobe station (Shin- stands for new, and not SHINkansen) for one of the next updates. It'll be 25tiles long.
Ehm, ah yes, your question. I was about to forget it.

My Shinkansen is Monorail based. it looks that way thanks to
Moonlinght's 新幹線MOD. ( scroll down until you find 新幹線MOD) It's a great mod. It gives a really good look to the monorail.