@jerril42
Nice suggestions. I use jumpers on breadboards quite often. I find they are more reliable than switches and easier to set up. the trick is to use double sided headers (pins on both sides are long).
@jdk8787
Yes, these are very useful. I have used 5 male header pins in a '+' shape, like you used with 3 in a row. That way the middle pin has 4 options (up, down, left or right) for connecting. In my case, I could power a DIY Arduino shield from a pair of screw terminals, or a voltage regulator on the sheild, or a USB port, or from the Arduino's 5V supply.
@TunioMir