The guitar's shape is a little bent and the strings are far from straight so I would efinitly consider using a straight edge. That's OK, after all these years i still can't draw a straight line XD Not sure what the guitar is resting on, bed sheets maybe? The shading is really lacking and the cat looks kinda quick. Add a little more detailing to the paws but still try not to take away from the guitar. Not sure if that's maybe a pot in the background but that could definitly use some work. Maybe even some details on the walls? I can certainly see something in this however. With some detailing you would really be able to see the whole "teenage life" depicted here. I love the idea, really great just needs some work. And welcome to Deviantart by the way! You can let me know if you need anything!