I made a stand for mine, for exactly that reason. I posted a picture of it here : https://retropie.org.uk/forum/topic/15975/my-first-bartop/2
I put a drawer in mine, which holds the keyboard & mouse, a cloth for dusting the screen, and a few other bits & pieces.
To be honest, there's not a whole lot to making a stand like that. Decide on the height you want, draw a side profile that you're happy enough with - get some graph paper and draw it out 1/10 scale (or whatever).
Cut it out, stick a top, bottom, back & shelves in the middle, and you're done.