The following is a rough breakdown of different popular pricing models in freelancing, as well as some pros & cons for each one.
✌️ Note: There is no ONE way to this. Much of your approach to pricing will be influenced by the type of clients & projects you work with, as well your own personality. Also, to this day I have not worked for/with agencies so I will update this doc based on your feedback.
It's the model we, and most of North America, is most familiar with.