I remember some of the local rider's ideas from the 1970s and early 1980s:
No handlebar tape - just bare handlebars.
Bar-end shifters used as brake levers (not recommended).
Front brake mounted backwards in the fork.
Bare plastic saddle, sometimes drilled for lightness & conformability.
Aero-section vintage wooden front rim.
Duct tape over the shoe laces.
Toe straps trimmed as short as medically practical.
Waterbottle stuffed upside-down in the back of the jersey, between the shoulder blades, to improve airflow behind the helmet (or bare head/cycling cap).
Cable housings trimmed as short as mechanically practical.
That's all I can recall right now.