I know that the crafting system is going to be more complex than will allow a simple UI to autopick items from your inventory for all possible combinations - however:
Why not have a default screen that will allow you to autopick your best tools and best items for a job when you select a recipe. If you lack those items or wish to experiment, have another button click on the recipe itself to allow you to experiment.
I am concerned about the clicktastic RSI risk of the current system to those of us that will most certainly be doing a lot of crafting with the current drag and drop everything method for every recipe. Making secondary materials like grass thread/string/twine, or cloth scraps/thread/string/twine could easily be made single clickable. If it is possible to improve on these recipes, then people might experiment, but there will be many times when you just want to make simple stuff (for new villagers for instance, or for practicing) and have no need of complex crafting.