Let me recap, so you are not confused. Recapping (or being repetitive is good - just like you did a hundred maths problems to understand a concept).
The best option for exit depends on whether you are a day-trader or away from your laptop. For daytraders, (not you), the ‘x’ or the 3-5 period low is best because they are screen watching. Some choose depending on how closely they are watching the screen the 3-5 period low, but re-enter, if the price goes back through the entry if the ‘X’ has not appeared. This is for daytraders watching pip by pip. This is not you. Others, who are more often away from the computer will just wait for the ‘X’ if their stop loss has not been hit.
Why have different rules? Because traders spend different time in front of a computer and want different things from trading. Some want to be ideal – ie sitting there all day. They like that. So the 3-5 period low (they pick 3 or 5 depending on how cautious they are, and that is personal). I prefer 3.
Now other traders, have a day job. They do not use 3-5 period low or ‘X’. They will use stop losses. A trailing stop loss. (we can worry about adding to winners separately).
The products to watch – 30m and 1h are best – are minor v minor or minor v major pairs. As you will not be working through the education material, one link to examine is this one: https://pipspredator.zendesk.com/hc/en-us/articles/115003142309-Learning-Trade-Selection-
So to be clear: For you – use the stop loss not the ‘x’ or 3-5 period low. Remember a trailing stop loss.
*IF you happen to be by the screen and want to screen watch, then the rule is 3-5 period low. Pick 5. And re-enter if the price moves back above entry and the ‘X’ not appeared. Also exit at ‘X’ if the stop loss is not hit.