Big drawing management: Favorite way to create new sketches in the middle of a larger drawing?

SketchUp Pro
10

Modeling technique has a tremendous impact upon model performance.

How do I make SketchUp run faster? — SketchUp Sage Site
https://sites.google.com/site/sketchupsage/faster

Money can by you a fancy new system.
But only good technique can make SketchUp perform at top speed.