Remember to employ a 15 - 20 min gap rulei.e. see how the market holds up the 1st 15 - 20 min i.e.

Draw 2 horizontal lines; one at the lows and one at the highs of the first 15 - 20 min. If the market can stay above the 15 min high candle bar, the it is considered positive and the gap could possibly hold up for the day , however if the market falls below the 15 min low, then the likelihood of the gap fading increases greatly.  Realize that this is just a technique only and doesn't work all the time!