Map icons
68 hours in and I'm still finding out things I didn't know (that's a good thing in my opinion). Just last night I found that if you hovered your mouse (I'm on a PC so I don't know what the equivalent is for consoles) over the mining sites, it shows the relative value of mining in that area (rich/moderate/fair/depleted). I thought all this time they were just generic markers, but if you mine/scan in a circumference of them, you can actually deplete the resources and the map marker will turn blue instead of white. Even if you don't deplete that area, hovering your mouse over the icon will show changes to the value from rich to moderate to fair. Most of you probably already know this, but it was just one of those small "wow" moments for me. Yes, I'm easily amused.
I also discovered that you can click on a white quest icon (non active in your journal), and make that the active quest, without going into your journal to change the objective. I find this very useful.