Getting approached by a client to do a mural can be extremely exciting but also daunting. For me, the easiest way to get started, is to use tools to help everyone visualize the final outcome of my work in the early stages of the project.
I used to simply sketch out my ideas on paper and then discuss these drawings in meetings to get feedback on them. Although this is a great method, and one I will still use time to time, I have began to switch to a more digital method of creating mock-ups which uses an iPad and Adobe Fresco.
To start off, I begin designing elements on my iPad, to create some characters, animals, etc. to show the client. After beginning this initial process though, it is invaluable to take photos of the actual walls you will be painting on and then superimpose the elements you have created on top to see what it will actually end up looking like. After doing this, it is easy to then add elements or change the ones you already created in order to better suit the space. This method is extremely helpful, particularly if you are doing murals on sections of the wall instead of the entire wall (like shown in the example below). Additionally, you can also superimpose a grid and adjust it to the dimensions of the room, which is helpful for artists who charge per square foot, but also for reference when you start painting!
This way of visualizing murals helps the client to get a better idea of what the end product will look like, and helps you be prepared for the task ahead of you.