This is a forex trading system I have used successfully, though I have only used it on the eur/jpy pair.
Indicators: 200 sma applied to closing price. 20 sma applied to high. 20 sma applied to low.
For long trades: look at the daily chart. Price has to be above 200 sma AND 20 sma (high). Switch to 4h chart. Look for inside bar pattern. Place buy order above inside bar pattern. Stop loss goes below the inside bar pattern. I use a 1:1 risk/reward ratio.
For short trades: price below 200 sma and 20sma (low) on daily chart. Look for inside bar on 4h chart. Sell order goes below inside bar pattern and stop loss above.
The one time I don’t use this strategy is when price is at or near key support/resistance levels, as this is a trend following strategy. At key levels I would either not trade at all, or look for reversals.
My reasoning for applying the 20ma:s to high and low is because the trend is more likely to have fully developed when those levels are breached. You can use trendlines if you are more comfortable with that.