[United Airlines Polaris Lounge]Hollis Johnson/Business Insider * United's Excursionist Perk lets you add an extra flight in your destination region for no extra miles. * It doesn't require any extra steps to use, only that you book with miles and create a multi-city itinerary. * If you have miles from the United Explorer Card or another source, like points transferred over from the Chase Sapphire Preferred Card, this is a great way to stretch their value. * Read more personal finance coverage. If you have the United Explorer Card like I do, the Excursionist Perk is a great way to get more from your miles. The Excursionist Perk adds an extra flight to a multi-city itinerary for no extra miles. For me, this helped to extend a recent trip to Greece to see Italy as well for just 60,000 miles and under $150 in taxes.SEE THE REST OF THE STORY AT BUSINESS INSIDERNOW WATCH: People are still debating the pink or grey sneaker, 2 years after it went viral. Here's the real color explained. SEE ALSO: * See all our credit card reviews — from cash-back to travel rewards to business cards — in one place * The Amex Green card earns valuable bonus points on travel and dining, but it faces stiff competition from Chase's Sapphire cards * Using points or miles for holiday travel can be tricky, but 5 strategies can help you stretch your rewards as far as they can go