Aiding the Obstetrician
Centrally on the bed, remove the lateral tilt once the baby is out.
Know where the emergency tocolytics are; difficult deliveries particularly of malpositioned babies can be tough on the obstetrician and the baby. Drugs like sublingual GTN and inhaled salbutamol can help relax the uterine contraction if it's impairing delivery.
Asking for Help:
Task fixation when things are not going to plan is something we all fall prey to. You may be more aware of how time is passing than the obstetrician facing a difficult LSCS, it's also easier to see the overall theatre picture - blood in the suction etc. Don't be afraid to ask if they would like another pair of hands, particularly when it's out of hours and the patient has only a spinal anaesthetic on board.