This might sound like a "shooting flies with a bazooka" solution, but in the long run, I find it worthwhile.
I use a half size breadboard with external power supply for larger projects. It's set up like a power strip and only supplies power, no circuit components are mounted to it. One side is 5vdc and the other 3.3vdc, with ground. The bench supply connects to the "red/blue" power rails which act as a "bus". I then jumper from the "bus" to the "matrix", the section with the letters and numbers, when I need to route power to separate devices. The "gutter" in the center separates the two and they are labeled as well. It's then a simple matter to jumper from the "power breadboard" to a standard breadboard with my circuit prototype(s) on it. By using the "matrix" I can keep track, using the letters and numbers, of where power is being routed to which device. Sounds a bit more complicated than it is in actual use and wonderful for complex projects with lots of circuits and the wiring needed to power them all.
Here's a simple way to turn a PC power supply into a bench power supply for RPi and Arduino projects: https://makezine.com/projects/computer- ... y-adapter/
You'll note the PC power supply already has the needed 5vdc/3.3vdc positive and grounds. 12vdc is a bonus.
This is working very well for a project where I'm using a RPi3B and 4 Arduino Uno devices along with sensor and motor boards and I have to supply both 5vdc and 3.3vdc to the circuits. 12vdc comes right off the bench supply to another circuit board for the motors as they need a bit heavier gauge wire to handle the higher voltage and current.