First, select the right waters. Rivers are divided into three regions: trout, barbel, and bream.
The barbel region is typically lowland, yet with a certain degree of a gradient. It has a water flow and temperature that ensure a good oxygen content.
In this region, the substrate is a mixture of silt and gravel and plants can take roots.
Additionally, the place must be ideal for sight fishing. There are huge barbel in the river Rhine, but they mostly thrive in depths that remain for fly angler unreachable.