Hi,
It was a long run, but I think I am nearly done with my castle. Can you give me tips to improve it, general feedback/errors etc?
Thank you all very much, my first months doing blender was so much fun :D
This really feels like a miniature to me. I guess it's not the idea.
Maybe the walls should have more bump to them, and the lack of background feels a little weird. Maybe adding some topography would help?
Yes, I m at the limit for my tress, blender starts to get slow, and they are just instances.
Maybe just some small green hills in the background..?
Thanks
You should definitely put your trees in a separate collection and hide these while you work on the rest I guess.
Have a look at these references for the background, maybe : 
I think it looks like a miniature, mainly because of the size of the trees.
Using low poly trees and a particle system, you should be able to fill up your scene.
This might be something to watch: https://www.youtube.com/watch?v=72LPW4S8bns
In another video he managed 20.000.000 trees, now your computer will probably not be able to handle that many, but you should be able to get enough in there.
