I use 3 EMA Long, Medium and Short EMA Short and Medium length are used for generating cross over signal just likes Golden and Death cross. The Long length EMA is applied to filter the longer term trend.
Users can adjust the EMA length to manually test the indicator as their wish. When uptrend the candlestick turns green and the first one is a buy signal , while downtrend, candle stick turns red. The first one is a sell signal.
The profit and stop loss might be taken as the candlestick turns to yellow. I think this is not a discretionary system. It's more likely semi-discretionary system. One can use it as signal, a trend guideline or the profit taking decision tools with easy visualization chart.
Note: Users can turn on/off the EMA indicators on the chart.