Im blue...

No not the song, but the background colour. As im working with a white scene i create a blue box behind the section that i am working on. Why you ask? Well to connect all the area of the cave system i either weld them together or i cheat by placing the vertex points in a particular way that the polygons cross each other. The blue box behind is used so i can see where there is a slight gap that needs closing.

It's unorthodox, but it works for me!