If you cannot avoid an attack, block or jam it. If you cannot block an attack, roll with it to avoid injury.
Eliminate unnecessary movement.
While it may be quite effective one on one, during a multiple attack, applying an arm lock, leg lock, or choke on one attacker will allow the others to do whatever they want to you.
Do not waste time on things that are non-productive, only use effective techniques.
Create hesitation by stunning your opponents with powerful attacks, loud kiai, etc.
Strike with conviction.
Use objects and obstacles around you to your advantage
Use intimidation. Act bigger than you are, such as they way cats fluff up. Stand tall and expand your chest.
Attack the leader first.
Stay away from the center, work from the flanks.
Read the reaction to your actions.
While more opponents mean more chances of your getting hit, more opponents also mean you have more potential obstacles to use. You may use one opponent as a shield against an attack from another opponent.