Emergency situations are not where your thinking brain is going to be functioning so get a plan in place well in advance. Make sure the whole family and the dog walker are all on board. 

The goal (obviously) is to avoid these situation by thinking ahead, using management, and being super proactive. Double check the gate in the backyard before you let your dog out. Install a baby gate near the front door for a double-door system. Don't let your dog off-leash where there is no secure fence. These are the most obvious and simple ones but the ones where people fail. 

If your dog escapes or takes off, you can try your recall (heck, try anything!). You can shout out all the favourite words your dog has to see what perks their ears up or turns their head. Keep up the excitement (dogs will come towards "exciting" and move away from "scary". Squeak a squeaker (always have a spare squeaker in your treat pouch pocket - it's a life-saver!!) and keep cheering. 

If your dog is spooked, chasing them will make them run away faster. It's hard though, because you need to keep them in sight so you don't lose them. 

Many people will say that lying on the ground is a great way to get Nervous Nellies back to you. Sprinkle stinky treats all around you so when they come and start eating, you can grab their collar and leash up. 

If your dog is having a blast, running away, be WAY more fun. Run in the opposite direction and make it a game too! Squeak the squeaker, jump around, run away, get low, get your food out and start being obnoxious about pretending to eat it ("Mmmmmm...yummy treats!!!") and sprinkling it on the ground.