1. The Bivvy
Ideally you should always find a flat spot to set up your bivvy. This will be more comfortable and safer, especially if you have get up quickly when a big fish takes and runs.
For ponds a distance of 10 to 20 metres from the rods is fine.
However, in rivers and large lakes you would be well advised to pitch your bivvy a good deal closer (10 metres maximum) so as to be much more reactive and not let the carp run into the snags. Check that once you're inside your bivvy you can see all your rods. Sometimes if you spot straight away that delicate bite or tiny beep that signals a run is imminent, it can mean successfully striking into a difficult fish that you'd otherwise miss if your bivvy were too far away.