what you have asked here is actually a very important question, this is a rather big subject - its all to do with the tf you have firstly identified the zone - and then taking entry based on a lower tf
not a simple answer but lets say you identifed supply on 4hr, and you noticed bearish enguilfing on 30min, the 30 min tf can produce a bearish pattern after 4 candles or 10 candles ........ or whatever - it all depends on how prices react and behave @ the zone
