I only once turn bowls, but have read guidance many times on forums. The common practice seems to be after turning, record the date and weight (I use grams which is allows better tracking than ounces) coat at least the end grain inside and out, or the entire surfaces, and place in a basement corner with little air circulation. Many have a number of bowls processed this way, so after the first 4-6 months there is a seemingly endless supply.