Go to the website of the airline with which you are a frequent flyer member. Locate the log in or sign in area on the airline's site and enter your log in name and password.
Create a username and password if you do not already have one. Just enter your personal information, contact information and your frequent flyer account number to begin using the online account management program.
Click on the frequent flyer option and view your account. From here you can view all of your past flights on this airline, upcoming reservations and the number of miles you have accumulated. After each flight you can check to see if your miles were updated, check for any mistakes or see if you have enough to begin using your rewards.