I was recently reading that when Hayao Miyazaki needs to paint something, he goes into the painting department and grabs random brushes and paint. He doesn't care at all what materials he uses because all that is important is his internal idea.
Taking this to heart, I've been experimenting by taking out materials that I thought were necessary and seeing if I really need them. You only really know if you need something by taking it away. And the majority of the time, what you really need is not external. Of course, a lot of outside resources make the job a lot easier and you may develop preferences. Just like when you go grocery shopping, you may not use a shopping cart, but it makes the job a lot easier.
This applies to a lot of situations, both artistically and not, when you think that you really need something, but remember "you only lose what you cling to."