Build A Project That I Am Working On!

I am working on building something for a friend, or group of friends, that will hopefully look good. I am looking for things that can help me improve on it. I used a randomly generated world for this, and found the most tactically defensable place (that's a word, right?) near spawn. I was hoping to have Grian see this, and give me some pointers to keep me going in the right direction. So... Any tips? (If you want to tell me anything specific, please use paint to point it out) Thanks!

 

I still sense missing detail and depth, but otherwise it's pretty good ._.

 

Pretty good, but the roof is really low and gives a sense of claustrophobia.