I'd say learning about weather. I didn't really think of it holistically before I got my cert. It helps to look at weather on a national, regional and then local level. There's lot's of information on weather.gov for example. I'm no expert but I do look at WX different today and I've seen some of it up close and personal, even VFR.
For example, at first rain and showers will keep you on the ground. But with experience, and hopefully a good, conservative pilot friend who understands wx better, you will learn those conditions can be very doable. What you see is a rain cloud doing what it does. To my right was 10+ miles viz and my out. By simply driving around it, I was in the clear in a minute or two.
With much lower hours that would have caused me to freak.