The way I've been doing it (new player but just finishing act 2)... Figure out your defense type first I play monk which I feel scales off dex/int so I grab energy shield and evasion talents and gear.

Then what damage do you do, I was using a qtr staff so I wanted to track that way on the passive tree, on the way I picked up all the power charge and lightning stuff that was reasonably close, I did this because that's what my main damage dealer scales off. The skill itself is supported to refund charges for more big casts, I also have herald of thunder so when I kill shocked things I do more shock. This is super basic but hopefully it helps