Here's a mock-up example of how I start my p to p builds.
I start with a raw .090 aluminum top plate. First lay out all the major components, If you're using transformers, place the power and output transformers in diagonal corners to maximize the difference between them. Try to keep all power components in a tight area around the power transformer. Signal wires shoud be tight, short, and as far removed from power components as possible. If you have to cross power and signal wiring, do so at a 90 degree angle. Use DC for all filaments. Good AC filament wiring is an art in and of itself. Be prepared to take several different attempts at your wiring. Do not leave connections unsupported or hanging in the air. Don't be afraid to rip things out and start over. As you progress, you will always see things that you could do better a second time around. Remember always to think about safety and heat dissapation.
Everybody that builds like this has a slightly different style. Rather than planning in advance where each particular small component or connection will be, I like to build a square of tie points around each tube socket and have a sort of connection point grid to work from. I like to keep everything at 90 degree angles if possible. For tie points, I like to use Soviet era Russian military connectors. Seller Sovcom on Ebay is a good source. I use a combination of 6 and 10 position connectors. They are pretty cheap, yet very high quality. Order 3 times as many as you think you'll need.
I like octal tubes rather than 9 pin miniatures. The sockets are much easier to work with. They also usually sound better.
Many miniatures have octal equivalents that can be used without any circuit modification. A 12AX7 is a 6SL7, a 12AU7 is a 6SN7., etc.. There is no direct octal equivalent to a 6S4, but half a 6BL7 comes close. Better than either of these would be to use a real power tube as an output device. A triode-connected EL34, or a trioide-connected 7591, which would be my personal choice (hey, it was good enough for McIntosh).
There's lots more, and I'm sure others have points and considerations I haven't even thought of. Eventually you need to go ahead and jump in. Post your progress or problems here. Don't be embarressed if it's not a work of art at first pass. We're here to help and keep you safe.