Good job m'friend, looking forward for more. Here are my opinions;
Picture 1: World tree? Pretty cool. I am not sure if it is supposed to mean that the tree is a the very top of a mountain, in that case it's a little plain for being top.
Picture 2: Too good, but the stones on/aside the waterall looks a little weird, but i have no ideas on how to improve. Is the water comming from under the castle or is it a small, small lake just beside?
Picture 3: That is so cool!! Probably the best screenie i have seen for a long time, and the model is pretty cool too.
Picture 4: You don't actually sees much, and i hope the whole terrain do not look exactly the same, not enough variation. But since it is what it is, good.
Picture 5: Spookie... Looks a little squarish though.
Picture 6: Nice one
you are good with combining doodads (other cases i have seen too).
It looks like i am the only one that says something bad. Sorry, but i am just trying to be onest and give constructive critics, even if u are a pro terrainer. I myself i trying to become a good terrainer, and these pictures give inspiration. Which i could give +rep, but i will just approve...