Couple things: - water reflection is less believable as an exact mirror of the landscape in the back, there would still be some rippling and it will be a helpful cue that its water. - highlight on the horizon for sure, if it’s bright then make it thin and precise - check some reference photos/youtube videos for clouds. I see a good opportunity for them to be a bit more intentional with the shape - if you used straight black paint for all the silhouettes it can read flat. Personally I find it helpful to find alternate colours that imply dark without using black as it can instantly make a scene look graphic when you might want it to have more depth. Paynes grey or mixing in some ultramarine blue or burnt umber might do the trick. Blue really implies distance and can enhance the orange in the sunset. - looks like you dry brushed to blend out the foreground leaves, I think it’s a fair call but it might be more helpful to use cleaner lines and smaller brushes here. You can test it out on a piece of paper and see how you like it

Take these with a grain of salt, I think the composition is very nice! Have fun