One method I'm using of helping to find the zones Jav is to look at the hourly chart on any pair. Find a big candle, either bullish or bearish that really stands out...a nice long one. In order to qualify, that candle should lead to a nice run in one direction or another. Once you find that key candle, the zone is usually fairly easy to spot.
Here's an example Jav. Originally, I had the 4 hour chart listed but the supply zone was pretty big. So I dropped to the hourly chart and was able to shrink the zone quite a bit. And I'm sure I can drop down to the 15 minute chart and narrow it down even more. Ideally, I like to see the zones around 20 to 30 pips. That narrows the stop loss down to acceptable levels.
One other thing to take note of Jav. When it doubt about a zone, just watch the price action. If you see a strong rejection of price at a particular level, look back and see if there's a prior supply or demand zone that agrees with the rejection. That can help us in getting our eyes sharpened to detect the zones ahead of time.