Doing a master copy is a very powerful way to deepen your painting skills. It is a practice that has been done for hundreds of years. Many of the old masters would study contemporary and past painters by doing master copy studies. It is not about creating a pretty copy of a painting, but about learning from it so you can incorporate your newfound knowledge to your own painting.
More information on Master Copy Studies:
https://artstudiolife.com/master-copy/
Relief sculpture master copy mentioned in video: https://www.youtube.com/watch?v=kVXP2MiUCp8&t=214s
Supplies used
Easel: https://amzn.to/40XTf7W
Palette: https://amzn.to/4fZz9yE
Brushes: https://www.rosemaryandco.com/oil-brushes?u=Artstudiolife
Primed Linen: https://shrsl.com/4rerq
Easel: https://shrsl.com/4rern