Also, as soon as possible, get the Sunpoint Plasma Drill from Smokefinger in Fortuna, it gives you a mining radar to help spot veins easier, allows you to get rare gems and has a stable beam that helps. You just need a bit of standing, I don't think you need to have ranked up with Solaris so it's easy to get.

Same logic on all open world areas, caves=more and better quality mining nods

Here’s how I’ve always done it:

Take out your beam, travel from one rocky place to another, looking for the icons on the minimap. Hasn’t failed me once.

Some people do caves, too.