How to get wool
You can get wool by shearing sheep, killing sheep, or crafting it out of string.
Automatic sheep shearing design
Dispensers can shear sheep if their hitbox is in the block in front of the dispenser.
How to build an automatic design
- Place down a dispenser facing horizontally.
- Lay down grass blocks 1 block lower than the dispenser.
- Build a pen out of fences.
- Lure sheep inside.
- Create any kind of redstone clock to power the dispenser.
- Place minecarts with hoppers underneath the grass to collect the items.