But what about hardware? There are certain things and connections that I feel I breadboard again and again and it really annoys me when I can't find a certain resistor or capacitor or diode or whatever when I make these structures. So I have decided to simply "encapsulate" a few parts of circuits and connectors and then use pin headers to connect to breadboards as needed. It's more effort now, but it should make future breadboarding less annoying in general.
MIDI Input Circuit
8-Bit R2R DAC
Game Boy DMG 4-Wire Sync Connector
2 Female DB9 Connector
15 Pin Male VGA Connector