There are two issues with days like 03/01 with huge range. One is being caught long when the market drops. The other is capturing the exceptional profit from a short position when price makes an exceptionally deep spike intra-day.
One thing you could do if trading with the trend long-term is check the slopes and positions of the 20 and 50EMA. If both are sloping downwards and the 20 is below the 50, its very hard to find justification for being long. As of 31/12, the AUD pairs looked like this -
AUD/CAD - 20EMA bearish, 50EMA bullish, 20 above the 50
AUD/CHF - 20EMA bearish, 50EMA bearish, 20 below the 50
AUD/JPY - ditto
AUD/NZD - ditto
AUD/USD - ditto
EUR/AUD - 20EMA bullish, 50EMA bullish, 20 above the 50
GBP/AUD - 20EMA bullish, 50EMA bullish, 20 below the 50
In summary, if you were trend-following AUD, you should have been short. I was not in AUD but I was short NZD across the turn of the year and it was my best trade so far in 2019.
As for capturing unexpected profits, that’s down to either watching your positions or related newsflow, or setting a take profit exit order way ahead of price.