At the moment I'm creating all my products over custom options.
Let's say I got 2 main - custom options for my product(Choose between standard model and custom model):
A - standard (colour, length.. is already configured)
B - custom -> The customer can decide which colour and length he wants to have.
So If customer picks option A - he doesn't need to care about the other option and if he picks option B he doesn't need to care about A. The point is, that B needs "Required Fields" so he must always check option B wherever he wants it or not. Of course you could just set the fields to non-required but that's not the way I want to go. Maybe he can get the choice to choose between those first main options first before he(if he chooses B) can chooses the custom option. And yes I could also create two products but that's not what I want.