This is how you can save on business trips:

-Join a business travel club. Joining a club will allow you to get some great deals on flights if you fly a lot. Since traveling is mostly about flying, you have a chance to save plenty of money that way.
-Avoid spending money in restaurants. Try to take some food with you instead. Having a few sandwiches with you can help you save plenty of money.
-Avoid any expenses that are not related to your business.
-While on the airport waiting for your plane, avoid visiting shops. This will allow you to avoid unnecessary expenses and buying things you do not really need. It is always better to read a book or try to do something on your notebook rather than visit airport shops.