Just spent the whole weekend wiring cars, getting them ready for season, or long trips through Utah. It's amazing how many really terrible wiring jobs there are out there. Especially the ones we get in that are done by 'professionals' of some type.
What I can say is that it is well worth the time and expense to lay a proper foundation when wiring. Start off with a good quality power distribution product that supplies power directly from a battery through a heavy duty relay, and provides fused protection. An Autotrend, Painless, Black Rhino, all give you a good professional start. I also suggest adding a ground block, they're cheap, easy, and can avoid a LOT of problems. We often see wierd electical problems that end up being caused by poor ground. They are often the most difficult to diagnose.
Putting all of your electrical connection through a fuse block and grounding block also gives you an added benefit, if you mount them in close proximity. All of your connections are localized into one area so if anything DOES go wrong, they're all in one place.
Also.... remember to write down what you did. What fuse position covers what accessories. What wire color(s) did you use. Make notes and keep them with your owners manual or maintenance records. It could save you LOTS of time, frustration, and mistakes. And whenever you have electrical work done, be sure to give a copy to your service rep and show them where everything is. It might, just maybe, also save you a few $$ down the road when a service center is installing something new, and all the connections they need are already there, all laid out and easy!