The "over water method" is very simple to setup. I use two variations. First, you can buy tubs from Coles or Woolies, that have grates in them. Simply fill the tub with some very damp substrate, place the grate ontop and sit the eggs on the grate. Like in this photo.
When the grate is sitting on the substrate like this, make sure the substrate isn't so wet, that water can splash the eggs.
The other is a purpose built tub. It's called a SIM incubation container. It has a grate suspended in the middle of the tub, you simply add water or very wet substrate to the bottom of the tub and place the eggs on the suspending grate. Like in this photo.
There are other "home made" ways of achieving this, just use your imagination at bunnings.
Know matter what method you use, holes in the tubs are not necessary, in my opinion. If you use holes, you need to cover them with "glad wrap". This allows gas exchange, but doesn't allow humidity to escape. But remember, the gasses expelled from the eggs, drop to the floor of the tub, so you will still need to open the tubs on a weekly basis and fan the gas out.
I have used tubs with holes in them, but I personally have greater success with no holes.
