Most use sheepskin wash mitts. Just pick and choose at the store which one is the fluffiest and nicest. Many brands all seem to sell the same mitt. They all have the same cuff, even the design on it, and all come from China. The Eurows at WalMart are great and I like the VROOM at Target. The one at Griot's, made in Canada looks nice. but I like to examine my mitts before I buy because no one mitt is the same.
I like sheepskin with 2 buckets to wash the car. One with suds, the other with clean water to rinse the mitt in before dunking back into the suds (known as the 2 bucket method). To help reduce swirling, use multiple mitts while washing - a couple for hood, roof and trunk and top portion of the sides - and another for the lower panels, bumpers, rocker panels, etc...