Orbiting is just flying a 360 degree turn.
The main issue as you already found out that there may be others behind you who may not be on exactly the same track as you. This can lead to you meeting up head on.
When asked to orbit and I am not sure about other traffic I usually just leave the circuit and join later. Rather spend a bit more time flying out of a congested area than trying to hold on to my slot in the circuit.
FD