How to attempt to avoid double brokering

What steps do you take to prevent double brokering in brokerages?

Are there policies and procedures in place to verify the credentials of carriers and ensure that loads are only being assigned to reputable and reliable carriers?

How do you ensure that your internal staff are aware of the risks of double brokering and the importance of avoiding it?

Is there additional training or education on this topic, and are there consequences in place for any staff who engage in double brokering?