As Jim Williams said, "The bit pushers have commented software; why not commented hardware?"
This post contains, in visual form, commentary on some examples of prototype construction technique and some commercial printed-circuit boards (with apologies to Jim Williams... see Appendix F, "Additional Comments on Breadboarding", in ).
Solderless breadboard. No.
Wirewrap. Really, no.
Prototyping breadboard with 45 rows of connections for dual-inline-package parts. For soldering together small circuits, these boards aren't bad. (Electronics Goldmine has these boards for $2.)
A better construction technique is deadbug on copper clad. This board is a simple oscillator that Jim Williams built in the deadbug style (a demonstration of ; also see ).
A pile of deadbug circuit boards built by Jim Williams (his lab bench really looked like this).
The good life. A custom evaluation board (this one is for the Analog Devices AD6816 networking chip with many SMA connectors).
The low-cost circuit board from a floppy disk drive (a single-sided PCB, that includes a "square-wave" trace around the motor for the position encoder).
Left: The one-transistor keypad from an original AT&T touch-tone phone (see ). Right: the circuit board for a more recent phone.
A ruggedized power supply (you can tell it's "rugged" from all the epoxy holding the parts in place).
The controller board from an inkjet printer, which includes a wide variety of IC packages such as the socketed DIP, several SOICs, and that EPSON ASIC in the middle with a million pins on tiny spacing.
The PCB inside a Spectral Synthesis ADDA2218, an 18-bit analog-to-digital audio converter, which uses colored FR4 (the color isn't just painted on, it's also impregnated in the fiberglass). I thought this was a neat touch, for a circuit board that only one-in-a-thousand customers would ever see (only those willing to void their warranty!).
 Jim Williams, "High speed amplifier techniques: A designer's companion for wideband circuitry," Linear Technology Corp., Milpitas, Calif., Application Note 47, Aug. 1991.
 Bernard M. Oliver, "The effect of mu-circuit non-linearity on the amplitude stability of RC oscillators," Hewlett-Packard Journal, vol. 11, no. 8, pp. 1-8, Apr. 1960.
 Jim Williams, "Max Wien, Mr. Hewlett, and a rainy Sunday afternoon," in Analog Circuit Design: Art, Science, and Personalities, Jim Williams, Ed. Boston: Butterworth-Heinemann, 1991, ch. 7, pp. 43-55.
 L. Schenker, "Pushbutton calling with a two-group voice-frequency code," Bell System Technical Journal, vol. 29, no. 1, pp. 235-255, Jan. 1960.