Understand what is deductible for tax purposes. You can deduct meals, lodging, transportation and any other incidental expenses, such as cab fare, that you incurred during business trips. You can deduct only 50% of the cost of your meals. However, if your employer gives you $10 for lunch and you spend $15, you can deduct the other $5 on your taxes.
Know what your employer will reimburse you. Most companies will give you something towards your business travel. For example, they may pay for your transportation and lodging, and give you an allowance for meals.
Get receipts for everything you spend on your business travel. No matter how big or small the item may be you should get a receipt. It may be advantageous to have later and you can always toss it if you find it isn't something you can use.
Keep a journal. It isn't enough to have a receipt for every item; you should have a record of everything you spend. Write down the dates of the business travel, where you went, the reason and then list the various expenditures.
Receive a receipt for car rental. If you need to rent a car to get from the airport to your destination, be sure you include it in your business travel's expenses. Make sure you list the car rental in your records.
Deduct all the expenses if you are self-employed. Understand that if your employer reimburses you for your business travel you can't deduct it on your taxes. However, if you are self employed all the business travel is deductible on your taxes. The records you keep of your business travel are for your employer and for your taxes. Anything not reimbursed by your employer can be claimed on your taxes.