Wool Farms
Wool Farms are slightly modified on Vanilla+ due to entity collisions being altered.
Due to this, designs like Ianxofours "cheap sheep wool farm" do not work.
Automatic Wool Farm
String Based Wool Farm
If you already have a Bartering Farm, you can craft the string it produces into wool.
Alternatively, you can turn a spider or cave spider spawner into a string farm.
With this farm, you would craft the string into wool.