@lobodyke
Its not really that hard, just click once the tower you want, and you should it now following your cursor, then click exactly where you want to build it.
@Astralite
I use the 1 space maze, which is to build no room for the electric fence, and then only use peon towers until you fill the whole maze
to start off, place 1 peon tower just outside the entrance, 1 space above it, 1 space below it, so that if you place another peon tower below it, you must place the next one, 1 space to the right. then continue making 1 space gaps until the end.
You should be able to fill the maze contently, leaving only about 3 spaces of waste.