MAD ELECTRICAL?

Having been an electrical guy all my life, I think it is fair to say that it is hard to get an answer from an electrical guy that doesn’t have “it depends” in it somewhere. If you ask a mechanical guy a question, you generally get a straight forward answer, not so much in the electrical side of the house.
With that said, I’m not sure there is necessarily a “best” way of improving the electrical wiring. It depends (see what I mean) on what you are trying to accomplish or optimize, how much effort you want to put in it, $$, and your skill level. Even the best modification will not work right if done poorly.
All of the mods in this thread will probably work fine. There are a few big things to watch out for:

1. Make sure EVERYTHING is fused that hooks up to the battery. This can be a fuse or a fusible link. There is a huge amount of power in a car battery. I have melted wrenches across a battery. It will also melt your wiring and start a fire. Very sad to lose a car this way.

My earlier comment on parallel fuses was a little vague. In the first three diagrams in the post, you only need to blow one fuse (or fusible link) to isolate a fault. I the last two diagrams you have to blow two fuses to isolate a fault, and it takes twice as much current. If you are not intentionally trying to double your current maximum for some reason, like a killer car stereo, maybe you shouldn’t do it. Once again, it is not a bad mod to increase current if you need it, but twice as big of a fuse is twice as much risk ( sort of).

2. High current connections ( above about 10 amps) must be done well, or they will overheat an burn up. Make sure your crimp lugs and splices are tight and solid. Pull hard on them after you crimp them. Some number of mine fail this test & I think I am good at it (maybe not...). I like to solder them, but that is not in everyone’s skill set.

3. Make sure your wiring has good physical protection. Use grommets on holes in metal to prevent shorts. Keep wiring away from exhaust manifolds and things that move. Don't pull it tight, leave some slack for stress relief.

4. The bulkhead connections are a well known weak link, and will probably fail on you if you don’t deal with them. You can bypass them or replace them as shown in this thread, just keep it fused.

I like my amp meter, so I am partial to designs that leave it operational. Personal preference.

While we are taking bulkhead connections, the other one that fails is the ignition power. Might be good to eliminate the bulkhead connection or bypass it while you are there. I think it is on the same connector on mine.

5. Modifications to the car. If you add or change something from stock, that can have an effect on the electrical system. If you replace your 30 amp alternator with a 100 amp unit, then your wiring may not be adequate anymore, even though it hooks up the same.

6. If you are not an electrical guy and all this makes your brain hurt, you can buy ready made wiring from at least one guy on this forum who has a lot of good feedback. Sometimes it is worth paying somebody else to do some of the thinking for you.