A couple of tips, since our tutorial turned out to be a bit too vague:
Every Gear is essentially a small spell that activates whenever its red tooth reaches the top.
- Weapon Gears fire.
- Aim Gears change where connected Weapons are aiming.
- Modifier Gears empower the next shot of any connected Weapon.
The important part is that Aim and Modifier Gears only affect Weapons they're directly meshed with. If two gears aren't touching each other with their teeth, they don't interact.
One more thing that isn't obvious at first: while editing your workshop, you can press Q and E to rotate the starting position of a Gear's red tooth.
This doesn't change what the Gear does — it changes when it activates. That timing is often the difference between a weak setup and a strong one.
For example, two rotating Weapons can accidentally keep shooting the same four lanes forever, leaving the diagonals undefended. Shift the timing a little, and suddenly one covers the cardinal directions while the other covers the diagonals. Small timing changes can make a huge difference, so don't be afraid to experiment!