I absolutely suck at aquascaping

[Guy]

If you have some pieces that you know for sure you'll be using on the bottom, wet down some sand paper, put it on a flat surface and shave your rock bottom to a flatness that works for you. It'll help with the stability and also give that look of and endless sand depth as rock seems to rise up from the sand bed.

I used 150 Grit that I had lying around.