WHat is the best mouthpiece and ligature for clarinet?

You'll need to essay on a music shop and claim on try some mouthpieces, and take a couple of different reeds as well. That bottle represent a huge difference. Take a piece that explores the exclusive range. Try jumps from low on excessive and vice-versa.

Ligatures can represent some difference, but they won't "improve" a mouthpiece/reed combo, partial change the sound slightly.

Only you experience the tone you want. You'll enjoy to experiment.