How to use Cardano's Plutus Playground?

To use Cardano's Plutus Playground:

1. Navigate to the Plutus Playground website.
2. Create a new project or load an existing one.
3. Write your Plutus smart contract in the editor, using the provided template as a starting point.
4. Use the simulator to define wallet values and script inputs.
5. Click 'Compile' to check your code for errors.
6. Click 'Evaluate' to run your contract in the simulator.
7. Analyze the results in the transaction log and final balances.
8. Iterate on your code based on the simulation results.

The Playground allows you to test and refine your smart contracts before deploying them on the Cardano network.