Having a decent set of jump cables in your car can save you a call out (with possibly charges) and long wait for the AA/RAC/Green flag to come and rescue you.
Knowing how to jump the car will also help:
If the battery is fully dead, leave connected, whilst donor is running for 5-20 minutes before attempting to start the car. Failing that try a decent battery trickle charger, if still nothing then most likely a new battery is needed.