You do not have to do anything. And kitbashing has nothing to do with block-out.
- blockout = no details; this is how my city will look like, roughly:
- kitbashing = details:
Take those parts, scale, rotate, mirror, clone, cut, scale again and make a cool highly detailed robot leg. Use the same parts to make a robot arm, head and torso. Combine all to make a robot.
Imagine the above is a bunch of rocks instead. You can combine them in new and exciting ways and make bigger and better, unique looking rock formations. Combine rock formations to make a cliff with a cave inside.
What you should consider doing is to find a way of designing levels you find most comfortable / enjoyable. Perhaps watch people designing levels:
