Your advice here has been very much appreciated. So now, one more challenge.
I have bought screw terminal proto shields. So far so good. Next project almost done.
But now I know I will go through several boards and chips and take several weeks trying to connect one sensor, one level changer, and one buzzer on that prototype board. I just cannot make reliable solder bridges - which in any case is a stupid way to do it, if I may say so. I can solder fine, but I have spent 50 years avoiding solder bridges, and making them, let alone reliably, is just not something I can yet manage. Even less if I need ONE 5V or 3.3V or ground connection to go to 5 different places. I just can't do it.
Any other advice? Better ways to do it? The boards I see with screw down terminals have no connected tracks - all just single, unconnected holes. Which to me is incredible. So I must be missing something really simple. What is it?