Gmoon wrote a hefty(22-step!) how-to for constructing your own sweet-sounding tube based guitar amp. Even if you’re not planning on specifically building this project, there’s a lot of really helpful details told from the maker’s perspective (even some informative regrets) –

No project is without lessons learned. In this case, I wish I had:
–Used a heaver, possibly stock, metal chassis.
–Substituted a 10 inch speaker.
–Used a turret board, instead of point-to-point. The more I modified the project, the more a tangled web it became. After this project, layout for turret board makes perfect sense–tubes on the back, controls on the front and the component board between….

Guitar Tube Amp on Instructables