Extro

Here's a section of mine, not sure if it will help or not: 

Grian made a good tutorial once I remember, and he's pretty epic style. 

Although, this is quite the build for a survival server (but not impossible, I was able to on a server I frequented). It also might not be your style.

I actually had a base inside a mountain back when Ethan had a realm. Took a lot of digging but basically I just had a staircase down to a big cavern, and a wooden bridge going over a big hole with magma blocks on the bottom (Niety fell down hehehe). There were also snow golems on either side to make it more intimidating I guess. After you crossed the bridge it was just a simple door and a pretty tightly-spaced, normal base. Multiple floors of it and it led up to the top of the mountain, where I had a glass ceiling and a small farm. Good stuff. I basically made the entire top of the mountain my base and put a couple automatic animal farms.