To make almond flour, which can be quite expensive in the stores, simply take the pulp remaining from making the almond milk and spread it out on the sheets of a food dehydrator.
Either put the pulp directly onto the fruit sheets that come with the dehydrator or onto a layer of parchment paper and then onto any of the dehydrator sheets.
Set the dehydrator to around 109 degrees. The pulp should be dried after about 10-12 hours. If it crumbles easily between your fingers, it's done.
Run the dried pulp through a food processor for a minute or so until it is powdery.
Store the flour in a tightly sealed glass jar and in a cool, dark place.