The most common causes (aside from poor driving habits) are
- bad timing
- bad sparkplugs
- low octane fuel*
- malfunctioning coolant temperature sensor
- blocked catalytic converter(s)
- malfunctioning MAP/MAF sensors
- driving with the parking brake engaged**
- having aftermarket wings on the car.
- tyres not inflated to the recommended pressure
- and a few others I can't remember
*Cars designed for low octane fuel won't benefit from high octane fuel, but cars designed for high octane fuel will perform poorly on lower octanes.
**Usually not because you forgot to release the parking brake, but because it may become stuck. Especially on cars with rear drum brakes.