A slight skew cuts cleaner
Feeding boards through your planer at a slight angle not only reduces surface chip-out, but also helps limit any snipe to one corner. You can also feed a board at a sharp angle; then straighten it somewhat after a couple of seconds. This only works, however, on benchtop planers with rubber feed rollers. Stationary models with steel rollers will not allow you to straighten a board once it starts feeding.