Zombies are attracted to anything that they can see, smell or hear. I suggest using this weakness to your advantage. Try using bell towers to lure bitters to different other sides of the town or city, as seen in The Walking Dead Video Game Season 2. If you ever come across fireworks, take them they can be used to overrun an enemies base by attracting zombies to their location.
You could make a spike or pitfall using noise and lights to attract them into a fall.
If your base is ever surrounded by zombies and escape is not an option, try using fireworks, speakers, or other noisy/bright objects to get them off your walls.
Zombies work in a dis-coordinated hoard, often traveling for miles in one direction, long forgetting what they were original chasing. It could be a rock falling or a random squirrel, but now there are 20…50…100…200 it just keeps getting larger and larger until they find something else to attract their attention.