Visit your airline's website to book your one-way ticket using your frequent flyer miles. Sign in using your username and password, which is required if you want to use your frequent flyer miles.
Click on the option that allows you to book flights using miles. The process is slightly different on each airline's website, but essentially the information required is the same.
Provide your travel information, which includes your departure city, arrival city and travel date. Click on the option to book a one-way ticket rather than a round-trip ticket. This option is given when you are entering your travel information.
Review your reservation. You will see the number of frequent flyer miles being deducted from your frequent flyer mile account to book your trip. Confirm your reservation and keep a copy of the confirmation page for your records.