My ZZ plant is finally looking happy after I stopped overwatering it

My ZZ plant is finally looking happy after I stopped overwatering it. I kept thinking it needed more water because the leaves looked a bit dull, but it turns out that was just dust. Now I water maybe once a month and it's actually pushing out new growth. Has anyone else struggled with underwatering versus overwatering with theirs? I'd love to know if there's a trick to telling them apart before things go wrong.