There is no right answer to this question, as this will differ depending on the exchange and your personal preferences. Generally, the most common payment method is bank transfer. This entails depositing money into your account via bank transfer and then buying a crypto asset instantly once the funds have arrived. Most exchanges that support bank transfer deposits will support payment providers like PayID and POLi, which are designed to speed up the bank transfer process. There are a number of other payment methods, however. Some exchanges allow users to buy crypto directly with a credit or debit card. This is often a lot more convenient than waiting for your deposit to process. However, it must be noted that this is often associated with higher fees. At the end of the day, your preferred payment method will depend on what you see as most important.