I agree with Moderator about the clean kitchen feel. Maybe the cabinets should be full of junk, some without cabinet doors even, and the space besides the cabinet could be occupied with book shelfs and stuff. Maybe add some blue prints and sketches about what kind of science project is he mad about.

I have the same problem as you with photoshop, it seems like there is no decent books or tutorials out there that completly explain the mystery behind texturing. Have you checked out a book call Digital Texturing and Painting by Owen Demers? It's one of the better ones out there, but I'm still looking for more.