By easily learning the following basics:

Do business or invest in your favorite vacation place and obtain a significant discount by deducting your travel expenses (including flight, hotel, car rental, and meals)
Travel expenses are deductible as long as the “primary purpose” of the trip is for business or investment purposes
Accordance to the IRS (tax agency), you have to spend more than half of your time “doing business” than on “vacation” activities
Document your trip by electronically saving your receipts, documenting the purpose of the trip and related business hours