Taken from the paper wrapping of a "Silver Beauty - Full Concave" razor, Sears, Roebuck & Co.

How to Use a Razor

Lay the razor as nearly flat as possible and cut in a sloping direction. Do not scrape or hold razor at an angle; this will spoil the edge, irritate the skin and cause the best razor to fail. It is highly beneficial to wash the face with warm water and soap before shaving, and time spent in softening the beard adds materially to the comfort of the operation. To keep a razor in good condition, it should be stropped before and after each shave and honed every four or five weeks. Do not overhone, a few strokes only are necessary. If a good quality hone and strop are used and proper care taken of the razor, it should give excellent service for many years.