I’m not talking about numbers crunching, things like target-dummy spreadsheet dps are completely irrelevant while leveling.
I’m talking about paying attention to how your character plays out, and envisioning how a talent adds or takes away from that, maybe with some help from a community website or a friendly fellow player. That exercise is enough to rule out most of these test builds.
When before you even get your first talent point, as a mage you realize that frostbolt slow and nova are key abilities, you don’t need to try out every talent combination to realize that augmenting your frost skills is the way to go.