Paul:
Hate when I do that !!
Forgot one silly little thing arrrrrrrrggggggggggh...
I sometimes print out the board and then turn it upside down and walk thru it to help spot some obvious goof. It is one trick that has caught some boo boos ..
I do not use schematics and auto-route ... I do fairly complex boards by just years of laying them out with paper tape and stick-ons on ye olde light tables.
So using CAD and putting down traces comes easy.... BUT one still can reverse one stupid trace - or NOT!!! Hey but I can do mazes faster then anybody - you know the kind they put on menus to keep kids busy whilst the junk-food is being prepared...