Oat flour is probably the flour I use the most. It has a fairly neutral taste and is extremely easy to make at home. I find it great especially for quick breads and cookies. Homemade oat flour tends to grind a little thicker and not as fine as store bought oat flour.
To Make: Simply put oats in a food processor and grind. It takes about 2 minutes to grind it to the finest consistency it will reach. After that, the flour will not grind any finer.
Storage: I store my oat flour in the freezer in a large, labeled freezer bag. It can keep for months like this.