How to choose a reliable freight forwarder?

Know your demand
How many shipments you have? Will you focus in one shipping channel?

Well know the forwarders experience
What is their network?  What is their experience in handling your shipment? Do they specialize in certain products and shipping channels?

Range of services
What are their services in details? How their services can benefit your business?

Risk management
How do they to risk management? What if they lost a parcel? How does the insurance work?

Communication
Efficient communication is very important. Will they respond fast and have a complete and understanding of what you want. If the communication is a problem, you can't expect that they can handle your shipment very well.

License and Permits
You want to have peace of mind. Ask if they have appropriate license, this can make sure that they are legitimate business at least.

Testimonials
You can ask them if they can share you some their customer reviews. Hopefully you can get some unbiased opinions from there.

Following above mentioned 7 points, you will know better about a freight forwarder, and make it even easier.