Try NOT leaving the layers panel open. Turn on the Layers toolbar instead. And then ALWAYS stay on layer 0. And model things on zero, then turn everything into groups and components. And then move those onto the desired layer through the layer toolbar. That way you never change from layer 0. But you can move components and groups easily onto the correct layer.
I like to do it that way,
Chris
Oh, and its still possible to get raw geometry to change layers accidentally. So then I use TIG's move all geometry to layer 0 plugin. It moves all loose geometry to layer 0, while leaving all components and groups on the layer they are on.