Simple and direct:
* Recycle to protect our planet.
* Recycling is easy, let's do it together.
Informative:
* Recycling helps conserve natural resources and reduces landfill waste.
* Every bottle, can, and paper you recycle makes a difference.
Motivational:
* Make a change, choose to recycle today.
* Be a part of the solution, recycle.
Humorous:
* Don't throw it away, give it a second life! Recycle.
* Recycling is like giving trash a makeover.
Choose the sentence that best fits your message and audience.