Charlie you have made the most confusing post.
Lets take an example. Lets say you have a north wind. This means wind is coming out of the north, and is normally cold and we like that, best wind ever, brings in new birds from the north. Ok, so with wind to your back, you must be on the north bank. If you are on the south bank, wind will be in your face. Birds like to land into the wind, so that is why you like the wind to your back. A cross wind is not bad either and something I prefer. When birds are landing and coming strait in, they will be looking right at you, vs a cross wind, they will not.
As a general rule, you do not want wind in your face, but there are times were this might work, and also you might not have a choice, and also might be the X.