Airfreight
Once you have a commercial invoice, this needs to be used for the air way bill and the customs clearance. It is less important for the air way bill to be correct as it doesn't hold quite the same weight as the seafreight bill of lading. That notwithstanding, you should ensure that things like the weight etc... are accurate to begin with.
Some other important aspects are ensuring that the dims are suitable for passenger flights as it is more expensive to send things on larger aircraft.
Also, security is extremely important! Some goods just cannot be flown so do check before making any commitments!
If your cargo is particularly dense then this may require secondary security screening which is more expensive.