My fee for in the USA is $300 day, plus air travel and a daily expense fee for food, hotel, rental car, etc.
Outside of the USA, the same per deim, however my daily fee is $400 a day.
Additionally, I charge a per mile fee to the airport, parking, and return to my home base.
Whatever the IRS is allowing as a per mile cost is what I charge, lately around 54 cents a mile.
If it is for a firm I am not farmilar with, there is an upfront deposit reguired that is based upon the amount of days, expenses etc that is one half of what I estimate to be the total cost of the consulting/training fee.
My terms of final payment are net 30 days, with a 2% per month interest charge for late payment.
All this is laid out in a written contract/agreement that must be signed and approved by me before any such travel/work is undertaken.
Grumpy