Summary

When you work on some project, most of the time, the flow is the following:

You start with modelling. You don't think about materials at this point, but you can change some objects' colours to make them more contrasting and visible.
After your model is done, you start work on material and light.
When the model, materials, and environment are done, you can set a pose for a character or a camera position.
And finally, you can set animation and export your project.