Cars are usually the straightforward part: a valid home license, often with an IDP depending on the country, a credit card for the deposit, and a minimum age commonly somewhere between 18 and 25 with young-driver surcharges below a threshold. Some companies also require the license to have been held for at least a year or two.
Scooters and motorcycles are where travelers get burned. In many countries, anything above a small engine size legally requires a motorcycle license category, not just a car license, and an IDP only translates the categories you actually hold. Tourist rental shops in beach destinations will happily hand you a scooter with no questions asked, but if you crash without the proper license class, travel insurance routinely refuses the claim and you may be personally liable, which is one of the most common expensive mistakes in Southeast Asia especially.
So check three things before renting two wheels: what license class the local law requires for that engine size, whether your home license plus IDP actually covers it, and what your travel insurance says about motorcycles. The official transport authority or your embassy page settles the legal question; the insurance policy wording settles the rest.