Just a tip, always consider the use for building / part / floor of your base. I've seen some great builds, with barely anything in because it doesn't fit or suit the layout.
Literally plan out what different rooms / areas you want. Think about what they need (e.g. coke oven needs a tall roof, decent bit of space/tree farm courtyard?)
Then find a layout that includes everything you need, and always leave empty rooms in case you need them in the future!
As for cool design styles, mountain builds are good, because you have to do far less external aesthetics, and get to focus more on the inside.
If you have Chisel 2, I recommend you use it. These are some examples: