I have a tried and true process. I use tinned duplex wire and run everything fwd to a central location usually near the controls. Power and ground bars fed by larger wire distributes power to carling brand breakers that double as switches. All the grounds and feeds are in one location also making things simple to check, connect and protect. I make my own switch panels and they have a common power bar on the feed side. Minimal connection load feeds go to all the parts. I solder and double heat shrink the connections. Some have lasted 15 yrs or more in a salty bilge environment. I also add a loop of wire for any future replacement of pumps etc. The x-tra length makes connecting new parts easier moved out of the bilge. I hate working in the bilge or any tight space. Being a charter boat Capt I had to have absolutely dead reliable stuff. Redundant bilge pumps and live well pumps are a part of that also. Can't tell you how many times it saved my azz. Just my way of doing it.