Book first. Most centres only test with a booking. Book on NaTIS online, or through your city if it runs its own booking system.
Bring your ID. Your green barcoded ID book or smart ID card (or passport and permit if you're not a South African citizen). Copies are usually not accepted.
Proof of address and photos. Some centres still ask for proof of residence and ID photos; many now take photos on site. Phone ahead if you're not sure.
Fees. Test and licence fees are set by each province and change from time to time. Check the amount when you book.
Eye test. Your eyes are tested at the centre. Bring your glasses or contact lenses if you use them.
Be early. Arrive well before your slot; late arrivals can lose their booking.