Mockup screenshot.. Not sure where to begin

[Limes]

Here's how I do sand dunes.. Notice the patterns in the sand, not trying to self promote only trying to give you a reference to help you with Pixelating sand dunes

[Kattlane]

Ohh, that looks helpful, thank you! I've kinda gone back to square one on this image. I feel like I need to solve the perspective of the scene first. It's a lot harder than I thought it would be because everything written about perspective makes it seem... too easy? I might be overthinking it. Anyway, thank you for the references I hope to have something to show later today!

[eishiya]

You're probably overthinking it! 1~3-point perspective is pretty easy, especially when it comes to organic forms like dunes. It's when you're dealing with blocky objects and many vanishing points per object that it can get complicated, but even then, you can usually eyeball things if you've got an eye for scale, which you can develop simply by being observant.