Examples

White has just played f3. This was a terrible mistake, as it weakened the diagonal g1-a7.
Black can now win by trading knights with Nxd4.
The queen has to recapture with Qxd4, and is lured to d4, where it can be pinned with Bc5.

Black can trade rooks with Rxf5+.
After White recaptures with Nxf5, the knight is lured to f5, where it can be pinned with Rf8.
The knight is lost, there is no way to defend it.

Related combinations

It is also possible to use a trade to lure a piece to a square where it can be attacked in a subsequent tactic other than a pin.
Instead of a trade, a decoy uses a piece sacrifice to lure a piece to a square.