Cover Art - for valves

Keep at it. As a former art student and Pro, never stop.
While you lack talent, you do not lack ideas. Keep at it. I mearly suggested you should have stopped when less was better.

Becoming good, at ANYTHING, requires time filled with practice. I used to deadacate endless hours behind my drafting table doing faces, animals, album covers on paper, denim jackets, pant legs, refrigerators, yes, refrigerators!
I did the Dead's "Oxamoxa" I think it is spelled. Hey, I got paid! Why he wanted it is beyond me besides loving the band, but I guess that is good enough.

Try an air brush. There in expensive and fun to use. Invest in some tape to create sharp lines.