* For woodworking: "The carpenter used a planer to smooth the rough edges of the wooden board."
* For a specific type of plane: "The planer with a helical cutter was faster and smoother than the traditional one."
* For a specific task: "She used a planer to flatten the surface of the countertop before applying the finish."
* For a metaphor: "His speech was a planer, smoothing over the rough edges of the debate."
The best way to use "planer" will depend on the specific context of your sentence.