aaa thank you very much for the great comment ;v; !
do a lot of experimenting with brushes till you get the grasp of each thing to draw C: (trees, rocks and the rest) and of course, lots of practice and patience. Currently, I see many errors in my picture here, but that's actually good, because it means I have a new way of thinking and what to do next time
I took a look on one of your pieces with a beach. It looks great! the advice I can give you is that you can give it more depth and a mix of harder and softer brushes instead of smudge-tool. The further away, the softer the brush (to give it a more blurred out effect). For stuff that is even more further away, a tint of the sky's color also helps to give depth C: But the composition is great and so the waves! Good work on that
And again, thank you very much!