On construction sites:
Hard hats, “sturdy” work shoes, safety glasses with side shields, hearing protection when applicable, full-body harnesses and lanyards (with permanent safety line) for work at height, work gloves when applicable.
Then we have to be aware of scaffold construction. In the US, work scaffolds are “certified” from day to day by specialists who have been trained in proper construction and support. In India… ha! – you sort of hold your breath on some of the scaffolds used there.
When working on “potentially live” equipment we use a Lock-Out / Tag-Out system to be certain that machines, electrical panels, wires, pipe lines, etc. will be safe for work and not remotely started, pressurized or otherwise energized.
For confined spaces, we make sure to have an outside “spotter”, as well as portable oxygen monitors and ventilation.
Welding and other hot / bright operations may require leather sleeves, heavy welding gloves, face shields and dark lenses. Flame or plasma cutting operations require less-dark lenses (and gloves). Grinding and abrasive cutting requires full face shields and safety goggles.
In the office:
Don’t drink too much coffee, and don’t piss off the boss.