The volatility of the EMini is about what, 4-5 points in an average bar variation in 5 minutes at peak times.
you do anything less than 4-5 points, you will get stopped out if you trade with 5 minute charts or basically 5-10-20 minutes.
I know a lot of traders trades resistance support levels (i.e. going long at support level, short on resistance and put a tight stop above it) - that's fine but keep in mind that they can see your stop orders. More often then not, i always see the pricing penetrate at least 1 point above the support/resistance level before bouncing back. You wlll get stopped out with 2 ticks. In other words, the people who pay the exchanges, firms, etc. can see your stop orders and they will take it out if it's to their advantage. (i.e. if you're 2 ticks aboev the resistance level, and they see a lot of stop orders, they will buy and then sell it to you at your stop 🙂 It happens all the time. That's why you see the candles close below the resistance/above support but the range of trades goes 2-3 ticks above/below it.