You can even cast downstream and employ a bow. The best explanation I have read was in Archi Braddocks’ book “Fantastic Feeder Fishing”, where a full chapter is dedicated to the method, “The Upstream Feeder”. Bob Roberts also goes into it in his levering book. Both books are well worth seeking out, but may be out of print, so you’ll have to get a secondhand copy/copies. The general principle is to feed a bow out and this, combined with the weight of the leger or feeder will enable you to get the balance so well tuned that only a slight pull will dislodge the feeder, giving that easy to read drop back bite. Whe you lift the rod to connect with the culprit, the direction of pull means that you are pulling the hook into the fish. If you are ever in the area, I would be happy to demonstrate the technique to you. It’s one of those things that is probably better shown than described. Having said that, the two sources mentioned do a far better job than I could.