Originally it was just caves, after that I found Etho and his honeycomb setup so I was like screw my caves, void age honeycomb labs for me. Set that up on seperate games. It was great cause the center of it was an amazing barrel sorting room.
After I got bored of the void age honeycombs I took a break from FTB, Come back and I just build a shape on the ground, build up, and make it look good. Takes more work especially when you don't have resources early on, and is a total pain in the rear to keep looking nice when all the machines start invading your house but it seems worth while.