Whenever I make them they always turn out ugly.
How do I blend them perfectly to the terrain?
And yes, I did use the search function, tyvm.

None.
How do I blend them perfectly to the terrain?

ForTheSwarm

Ultraviolet -- That's strange, it looks like you targeted the base image file (sometimes people make the mistake of just using the imgur page link which doesn't work for embedding) but it still didn't work it sounds like.
NudeRaider -- I think SEN has trouble with https or hotlinking is forbidden. It certainly is nothing about the size, it just fails to get any size. You can get it working if you use imgur and include the actual image link for the img tag. Like this: [img=https://i.imgur.com/ddYqXZa.jpeg]
lil-Inferno