I have used red head metal plaster board rawl plugs. The kind that flare out flat when you screw the bolt in.
I now need to remove them. Is there a trick to remove them so I can reuse them or take them out cleanly at least?
Keep pressure on the screw while you unscrew it. It will force the plug to unfold, making removal possible. Once the plug is fully unfolded, the screw will come out no matter how much pressure you keep on it.
If for whatever reason that fails to extract the plug, you can usually do less damage by pushing the plug it into the wall versus trying to pull it out.
That is a good suggestion but often the rawl plug doesn't unfold fully. In order to push the plug with minimal damage is to proceed as instructed above, pull partially the plug out and with pliers bend (and a a result break off) the external (what is visible when the plug is fully screwed into the wall) plate/face of the plug. You can then push the plug right in the wall without any damage whatsoever.