When I did stocks I'd put in a trailing stop loss that would sell any time the stock dropped by 10% below the purchase price. If the stock increased in value I'd keep bumping up the stop loss at 10% below the highest value the stock had risen to and take my profits when the stock value fell. My mistake early on was not taking into consideration some stocks day to day volatility in which case swings of 10% could result in buying and selling literally within a few hours on the same day. In such cases you will be getting hosed on transaction fees.
This post was edited on 5/22 at 10:15 am