How to pick best freight forwarder

As the subject says, I’m trying to figure out how experienced Amazon sellers evaluate freight forwarders on Alibaba for China to Amazon FBA shipments.

1.Where do you normally contact them?

2.What specific things do you discuss before confirming an order with them?

3.How do you verify that the quoted transit time is realistic and not just a sales pitch?

4.What terms do you always get confirmed in writing before cargo pickup?

1. How do you protect yourself from surprise charges after the shipment is already in their hands?

6.How do you tell the difference between a forwarder that’s actually reliable and one that just has good Alibaba reviews?

Any overall advice or lessons learned from your own experience would be appreciated.