Speaking of Lyft… Through Christmas Day, you can earn 10 Delta SkyMiles per dollar on Lyft rides to or from a US airport, and 3 miles per dollar on other US Lyft rides, if you sync your Delta and Lyft accounts here and enter the promo code SKYMILES10X in your Lyft app. This is in addition to any points you’d earn from your credit card. After the promotion ends, you’ll earn 1 Delta mile per dollar on US Lyft rides and 2 miles per dollar on airport rides. Not a bad bonus.